Fabrication and application of a non-contact double-tapered optical fiber tweezers.

A double-tapered optical fiber tweezers (DOFTs) was fabricated by a chemical etching called interfacial layer etching. In this method, the second taper angle (STA) of DOFTs can be controlled easily by the interfacial layer etching time. Application of the DOFTs to the optical trapping of the yeast cells was presented. Effects of the STA on the axile trapping efficiency and the trapping position were investigated experimentally and theoretically. The experimental results are good agreement with the theoretical ones. The results demonstrated that the non-contact capture can be realized for the large STA (e.g. 90 deg) and there was an optimal axile trapping efficiency as the STA increasing. In order to obtain a more accurate measurement result of the trapping force, a correction factor to Stokes drag coefficient was introduced. This work provided a way of designing and fabricating an optical fiber tweezers (OFTs) with a high trapping efficient or a non-contact capture.

Calculation of the radiation forces on a microsphere in the evanescent field of an optical nanofiber by ray tracing.

We use ray optics to calculate the radiation forces on a dielectric microsphere in the evanescent field of an optical nanofiber. We theoretically demonstrate that the gradient force may attract the microsphere onto the fiber surface. The scattering force may transport the microsphere along the fiber and in the light propagating direction. The impact of the sphere-fiber distance, sphere radius, and fiber radius on the scattering and gradient forces are investigated. The radius of nanofiber can be optimized for particle transportation.

[The effect of phospholipid transfer protein on cigarette smoke extract induced epithelial-mesenchymal transition of rat alveolar type â ¡ cells].

OBJECTIVE: To investigate the effect of phospholipid transfer protein(PLTP) on cigarette smoke extract(CSE) induced epithelial-mesenchymal transition(EMT) in rat alveolar Type Ⅱ cells (RLE-6TN). METHODS: CSE of different concentrations (0%, 0.25%, 0.5% and 1%) was co-cultured for 2 or 3 days with RLE-6TN, either pre-treated or not pre-treated with siRNA-PLTP for 6 h. Expression levels of E-cadherin mRNA and Vimentin mRNA were examined by RT-PCR, while expression levels of PLTP, E-cadherin, N-cadherin and Vimentin were examined by Western blot. RESULTS: Our results showed that the expression of E-cadherin mRNA decreased in CSE-treated groups: 1.01±0.05, 0.74±0.05, 0.65±0.03, 0.30±0.08 respectively at different concentrations of CSE (0 %, 0.25%, 0.5 %, and 1.0%); while the level of Vimentin mRNA increased significantly in 1% CSE treated cells(1.88±0.49), compared with control cells (1.01±0.20). Treatment with CSE at different concentrations (0%, 0.25%, 0.5% and 1%) showed that the protein levels of PLTP were 0.42±0.02, 0.89±0.25, 1.08±0.18, 1.61±0.06 respectively; those of E-cadherin were 1.61±0.04, 1.08±0.10, 0.62±0.08, 0.68±0.17, respectively; those of N-cadherin were 0.60±0.14, 0.57±0.26, 0.88±0.30, 1.94±0.54, respectively; and those of Vimentin were 0.61±0.05, 0.98±0.16, 1.07±0.14, 1.34±0.19, respectively; all P<0.05 when the 1% CSE group was compared with the control group. EMT induced by CSE was significantly inhibited by siRNA-PLTP. CONCLUSION: PLTP may be involved in CSE induced EMT of rat alveolar cells.

Chest wall recurrence location and the lower-bound target of preventive radiotherapy after transverse incision in modified radical mastectomy.

We investigated the relationship between the lower-bound target of preventive radiation to the chest wall after modified radical mastectomy with a transverse incision and preoperative breast carcinoma characteristics to provide a basis for reducing radiation injury to neighboring tissues and individualizing preventive chest wall radiation targets. We analyzed the relationship between clinical stage, pathology, diseased region, condition of vessel tumor embolus, sex hormone levels, HER-2 expression levels, receipt of chemotherapy, and the distance of local chest wall recurrence under the edge of the transverse incision in 112 patients with local chest wall recurrence after radical mastectomy. There were 64 cases (57.1%) with local chest wall recurrence within 3 cm below the transverse incision fringe, 31 cases (27.7%) within 3-5 cm, 14 cases (12.5%) within 5-7 cm, and 3 cases (2.7%) exceeded 7 cm. There were statistically significant correlations between the distance from the focus of the chest wall recurrence to the inferior margin of the transverse incision and the T stage, HER-2 expression levels, and receipt of chemotherapy. For more than 97% of patients undergoing radical mastectomy with a transverse incision, the distance of local chest wall recurrence under the edge of the transverse incision was less than 7 cm. To accomplish individualized treatment in defining radiotherapy targets, we should pay attention to T stage, HER- 2 expression levels, and the receipt of chemotherapy when determining the lower-bound location of the target for preventive chest wall radiation after modified radical mastectomy with a transverse incision.

Synchronization of time-delayed chemically coupled burst-spiking neurons with correlated noises.

Synchronization of two time-delayed chemically coupled neurons with burst-spiking states is studied. Different from the previous study by N. Buric et al. (Phys. Rev. E 78, 036211 (2008)), it is found that exactly synchronous burst-spiking dynamics can occur for small coupling strengths and time delays. The results are confirmed by common time delays and non-equal time delays. When common noise is added to the two neurons, synchronization is enhanced as noise strength is increased. But the results are different for larger time delay and smaller time delay. When noises are correlated, it is found that only strong noises with large correlation coefficient can induce exact synchronization. Even one percent of independent noises can influence synchronization much.

Quantification of deposition of neutrophilic granulocytes on vascular grafts in dogs with 111In-labeled granulocytes.

A new radioisotopic technique has been developed for quantification of deposition of neutrophilic granulocytes on vascular grafts. Nine healthy mongrel dogs underwent bilateral femoral artery resection and reconstruction with grafts of femoral vein and Gore-Tex. Pure granulocytes that had been separated from whole blood by centrifugal elutriation were labeled with 111In-tropolone in plasma. The granulocyte harvesting efficiency was 25 +/- 12%, and the labeling efficiency was 87 +/- 7%. Three hours after injection of labeled granulocytes and 2 hours after reperfusion, the grafts were harvested and cut into several segments for study of areas of anastomoses and midsections. On the basis of the radioactivity in the blood and in anastomotic and graft sections, the area of graft sections, and the neutrophilic granulocyte and differential leukocyte counts, the number of neutrophilic granulocytes adherent to a unit area and the total number of neutrophilic granulocytes on graft sections were calculated. These quantifications of the deposition of neutrophilic granulocytes indicated that the midsections of Gore-Tex grafts retained more neutrophilic granulocytes than did the midsections of vein grafts. Although the anastomotic areas retained more neutrophilic granulocytes than did the midsections of vein grafts, the opposite finding prevailed for the Gore-Tex grafts. A major fraction of neutrophilic granulocytes on Gore-Tex grafts was incorporated into thrombus. Semiquantitative information obtained by scintigraphy of the deposition of neutrophilic granulocytes on vascular grafts also confirmed this observation.

VEGF and endostatin levels in wound fluid and plasma after breast surgery.

Angiogenesis is essential for wound repair after surgical trauma. Vascular endothelial growth factor (VEGF) and endostatin are endogenous angiogenic factors involved in the initiation and completion of angiogenesis. The aim of this study was to examine the local and systemic VEGF and endostatin profiles in patients undergoing surgery for benign and malignant breast processes. A total of 16 patients with or without cancer underwent breast surgery. Group I: eight patients with primary breast cancer underwent a simple or radical mastectomy according to Madden including dissection of axillary lymph nodes. Group II: eight healthy female-to-male transsexuals underwent subcutaneous mastectomy. VEGF and endostatin levels in plasma and wound fluid were determined. In both groups VEGF levels in wound fluid were significantly higher compared to postoperative plasma levels, whereas wound fluid endostatin levels were lower than plasma levels and decreased progressively after surgery. In both groups plasma VEGF and endostatin levels did not change significantly before and after surgery. The local VEGF increase and endostatin decrease observed immediately after surgery appears to be a physiological response to operative trauma, which can be studied more profoundly in locally generated fluid than in blood. This process did not seem to be influenced by the type of process (cancerous or non-cancerous) involved in the surgical intervention.

Radioimmunodetection of human melanoma with indium-111-labeled monoclonal antibodies.

Our purpose in conducting this study was to evaluate the efficacy of an 111In-labeled murine monoclonal antibody directed against a high-molecular-weight glycoprotein in localizing metastatic melanoma in 15 patients with previously documented disease and to determine the effect of antibody mass (2.5, 5.0, and 10.0 mg) on blood clearance, biodistribution, and lesion detection. Five mCi of 111In-antibody were infused over 1 hour, and patients were scanned at 24 and 72 hours after injection without computer enhancement or background subtraction techniques. No significant differences in the organ distribution, urine excretion, or plasma disappearance curves were noted at the three antibody dose levels. There were no acute reactions. The scan detected tumor in 9 of 12 (75%) patients with active disease, and 26 of 33 (79%) lesions greater than 1 cm. Patient management in 3 of 15 (20%) of patients studied was changed as a result.

Systemic and peritoneal inflammatory response after laparoscopic or conventional colon resection in cancer patients: a prospective, randomized trial.

PURPOSE: This study was designed to evaluate differences in both the peritoneal and systemic immune response after laparoscopic and conventional surgical approaches. METHODS: Patients with a primary carcinoma were prospectively randomized to curative laparoscopic (n = 12) or conventional (n = 14) colon resection. The proinflammatory cytokines interleukin-6, interleukin-8, and tumor necrosis factor-alpha were measured in the peritoneal drain fluid and in the serum. C-reactive protein and leukocyte counts and the differences in leukocyte subpopulations and expression of human leukocyte antigen-DR on monocytes were measured perioperatively. RESULTS: Significantly higher levels of proinflammatory cytokine were found in the peritoneal drain fluid than in the circulation after both procedures. Serum interleukin-6 and interleukin-8 levels were significantly lower 2 hours after laparoscopic surgery than with the conventional procedure. Postoperative cellular immune counts and human leukocyte antigen-DR expression normalized earlier after the laparoscopic approach. CONCLUSIONS: The systemic proinflammatory concentrations after both surgical approaches represent only a small fragment of what is generated in the peritoneal drain fluid. Even if the immediate levels of proinflammatory cytokines in the serum are significantly lower in the laparoscopic group, the same cytokines locally produced showed no differences, which suggests that the two intra-abdominal approaches are equally traumatic. No differences in cellular response were observed between the groups.

Systemic and peritoneal angiogenic response after laparoscopic or conventional colon resection in cancer patients: a prospective, randomized trial.

PURPOSE: Angiogenesis is essential for wound healing. Vascular endothelial growth factor and endostatin are both endogenous angiogenic factors thought to be involved in the initiation and termination of angiogenesis. The aim of this study was to assess the local and systemic angiogenic profile in patients undergoing laparoscopic or open surgery for colon cancer. METHODS: Patients with primary colon carcinoma were prospectively randomized to curative laparoscopic (n = 12) or conventional (n = 14) resection. Vascular endothelial growth factor and endostatin levels in serum and wound fluid were investigated. RESULTS: In both groups vascular endothelial growth factor levels in wound fluid were significantly higher than postoperative serum levels, whereas endostatin levels in wound fluid were lower than serum levels and decreased progressively after surgery. The vascular endothelial growth factor levels in wound fluid measured at Day 4 were significantly higher in the laparoscopy group than in the laparotomy patients. CONCLUSIONS: Wound healing is associated with a strong local increase in pro-angiogenic factors and a decrease in antiangiogenic factors. The investigation of locally produced factors offered greater insight into the process of angiogenesis during wound healing than could be acquired from the circulation.