No abstract available.
Cell Adhesion* ; Ischemia* ; Microscopy, Video* ; Reperfusion*

BACKGROUND: Chemotaxis is one of the cardinal functions of leukocytes, which enables them to be recruited efficiently to the right place at the right time. Analyzing chemotactic activities is important not only for the study on leukocyte migration but also for many other applications including development of new drugs interfering with the chemotactic process. However, there are many technical limitations in the conventional in vitro chemotaxis assays. Here we applied a new optical assay to investigate chemotactic activities induced in differentiated HL-60 cells. METHODS: HL-60 cells were stimulated with 0.8% dimethylformamide (DMF) for 4 days. The cells were analyzed for morphology, flow cytometry as well as chemotactic activities by a time-lapse videomicroscopic assay using a chemotactic microchamber bearing a fibronectin-coated cover slip and an etched silicon chip. RESULTS: Videomicroscopic observation of the real cellular motions in a stable concentration gradient of chemokines demonstrated that HL-60 cells showed chemotaxis to inflammatory chemokines (CCL3, CCL5 and CXCL8) and also a homeostatic chemokine (CXCL12) after DFM-induced differentiation to granulocytic cells. The cells moved randomly at a speed of 6.99+/-1.24 micrometer/min (n=100) in the absence of chemokine. Chemokine stimulation induced directional migration of differentiated HL-60 cells, while they still wandered very much and significantly increased the moving speeds. CONCLUSION: The locomotive patterns of DMF-stimulated HL-60 cells can be analyzed in detail throughout the course of chemotaxis by the use of a time-lapse videomicroscopic assay. DMF-stimulated HL-60 cells may provide a convenient in vitro model for chemotactic studies of neutrophils.
Chemokines ; Chemotaxis ; Dimethylformamide ; Flow Cytometry ; HL-60 Cells* ; Humans ; Leukocytes ; Microscopy, Video ; Neutrophils ; Silicon

Papaverine has been widely used to reverse cerebral vasospasm because of its vasodilatory effect. However, its therapeutic value has been limited at least in part. In a previous study, low concentration papaverine was observed to potentiate a phorbol dibutyrate induced constriction of rat cerebral microvessels in vitro. The purpose of this study was to investigate the above effect in large cerebral arteries. Rabbit basilar artery was constricted in vivo by topical application of phorbol dibutyrate. The basilar artery was visualized using transclival exposure, and its diameter monitored using videomicroscopy. At the concentrations of 50, 100, and 500 M, papaverine elicits a dose-dependent vasodilatation of basilar artery that had been preconstricted with 20 nM phorbol dibutyrate. Subsequently, the above procedure was repeated, using lower concentrations of papaverine at 0.1, 1 and 10 M with no observable consistent potentiation effect. These results suggest that structural and pharmacological differences between large cerebral arteries and cerebral microvessels may contribute to the differences in their vasospastic response.
Animals ; Basilar Artery* ; Cerebral Arteries ; Constriction ; Microscopy, Video ; Microvessels ; Papaverine* ; Rats ; Vasodilation ; Vasospasm, Intracranial

OBJECTIVE: The UE Video Stylet VL400-S2 (UE Medical Devices, Newton, MA, USA) and Ambu aScope (Ambu, Copenhagen, Denmark) were recently introduced rigid video stylets and single-use fiberoptic bronchoscopes, respectively. To compare the utility of the two sets of equipment, this study conducted a randomized cross-over study using a manikin. METHODS: Twenty-eight novice doctors performed tracheal intubation on an airway trainer manikin (Laerdal, Stavanger, Norway). The sequence of intubation devices was randomized. The following data were measured and recorded: time to complete tracheal intubation (primary end point), overall success rate, time to see the glottis, and time to tube passage. RESULTS: The video stylet (24 seconds; interquartile range [IQR] 18–36) showed a significantly shorter completion time of the tracheal intubation than the fiberoptic bronchoscope (43 seconds; IQR, 32–84) (P<0.001). The overall success rate of tracheal intubation was 96.4% (27/28) in the video stylet and 82.1% (23/28) in the fiberoptic bronchoscope, and the cumulative success rate over time to complete intubation was significantly higher in the video stylet (P<0.001). CONCLUSION: The video stylet was superior to the fiberoptic bronchoscope in terms of the time to complete and the cumulative success rate of intubation for novice operators in manikin model. Further research will be needed to determine the degree of education required to use fiberoptic bronchoscopy.
Bronchoscopes ; Bronchoscopy ; Cross-Over Studies ; Education ; Glottis ; Intubation ; Intubation, Intratracheal ; Manikins ; Microscopy, Video

BACKGROUNDThe operating microscopes have been applied to modern surgery for nearly a century. However, generations of microsurgeons have to flex their necks and fix their eyes on the eyepieces of a microscope continually that leads to physical and mental fatigue during a long operation. Stereoscopic three-dimensional (3D) media provides more ergonomic working environment, subsequently, resulting better performance in tasks and more accurate judgment. In this study, an alternative method of magnification was analyzed using a three-dimensional microsurgical video system and compared with the traditional method under microscopy to evaluate the availability and feasibility of a 3D microsurgical video system for microvascular anastomosis.

METHODSForty Sprague-Dawley rats were randomly divided into four groups with each of 10. In 20 rats, 10 femoral artery anastomoses with a conventional microscope (arterial microscope group) were compared with that of 10 femoral artery anastomoses with a 3D microsurgical video system (arterial 3D group). For the other 20 rats, 10 femoral vein anastomoses using a conventional microscope (venous microscope group) were compared with that of 10 femoral vein anastomoses using a 3D microsurgical video system (venous 3D group). The arterial and venous microscope groups were considered to be the control groups. The arterial and venous 3D groups were the experimental groups. The examined criteria were as follows: anastomotic time, patency right after the procedure and 10 days later, number of sutures, vessel caliber, and pathological features.

RESULTSThere were no differences between the operating equipment with respect to vessel caliber, anastomotic time, patency rate, number of sutures, and pathological changes in either the small arteries or veins. The average arterial anastomotic time of the arterial microscope group and arterial 3D group was 34.21 and 33.87 minutes, respectively (P > 0.05). The average venous anastomotic time of the venous microscope group and venous 3D group was 29.95 and 31.50 minutes, respectively (P > 0.05).

CONCLUSIONSA small vessel anastomosis can be performed successfully with the help of a 3D display system. Although the vascular anastomotic time did not demonstrate a significant difference between the groups, the 3D microsurgical video system offers another option to improve the working environment for surgeons. Further development of our 3D monitoring system should focus on a higher resolution and better flexibility.

Anastomosis, Surgical ; methods ; Animals ; Female ; Femoral Artery ; surgery ; Femoral Vein ; surgery ; Microscopy, Video ; methods ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: There is increasing evidence that the omega-3 polyunsaturated fatty acid, eicosapentanoic acid(EPA), induces relaxation in vessels from various animal models as cardiovascular protective nutrients. In vivo study was undertaken to investigate the potential therapeutic application of EPA to resolve vasospasm. METHODS: The basilar artery was visualized using transclival exposure, and its diameter monitored using videomicroscopy. Rabbits were divided randomly into seven groups:1) normal rabbits basilar artery treated with topical application of 100nM/L EPA only;2) normal rabbits basilar artery treated with 20nM/L phorbol dibutyrate(PDB), then 20 nM/L PDB+100nM/L EPA;3) normal rabbits basilar artery treated with 80mM/L KCL, then 80mM/L KCL+100nM/L EPA;4) normal rabbits basilar artery treated with 20nM/L endothelin 1(ET-1) only;5) normal rabbits basilar artery treated with 20nM/L ET-1, then 20nM/L ET-1+100nM/L EPA;6) subarachnoid hemorrhage(SAH) rabbits basilar artery treated with artificial CSF only;7) SAH rabbits basilar artery treated with 100nM/L EPA. RESULTS: In normal(non-SAH) rabbits, EPA:1) had no effect on basal tone;2) did not reverse KCL or PDB-induced constriction;and 3) substantially reversed ET-1-induced constriction. The diameter of normal rabbit basilar artery was 779.1+/-17.9nm(mean+/-standard error). After SAH, the mean diameter was 521.0+/-32.5nm. The addition of EPA reversed this SAH-induced constriction to 80.4% of baseline diameter. CONCLUSION: These results suggest that EPA induces relaxation in cerebrovascular arteries constricted with ET-1, and that it prevents and partially reverses SAH-induced vasoconstriction.
Arteries ; Basilar Artery ; Constriction ; Eicosapentaenoic Acid* ; Endothelins ; Microscopy, Video ; Models, Animal ; Rabbits ; Relaxation* ; Spasm* ; Subarachnoid Hemorrhage ; Vasoconstriction

Introduction of patch-clamp techniques allowed an increase in resolution of membrane current recordings. However, the technique was limited by apparent need for direct contact of pipette with cell membrane. Thus, this technique was restricted to isolated or cultured cell preparation. Although much has been achieved with such preparations, the studies of synapsis between cultured cells are undefined. Many of these problems were overcome by application of patch-clamp techniques to brain-slices. The use of high-resolution optics allowed visualization of cells to be recorded. It was possible to remove tissue covering cells and record currents in synaptically connected neurons. The brain-slice technique has greatly facilitated the investigation of electrical properties of neurons and the analysis of synaptic transmission between neurons. "Blow and seal"technique, when combined with infrared differential interference contrast video microscopy, permits recording of membrane potential and currents, not only from large cell body of neurons, but also from small processes. The technique offers many advantages, such as the case with which patch-pipette recordings can be made, the possibility of identifying cell type prior to recording and finally, the ability to visualize and record electrical activity from different compartments or from more than one site in the same neuron.
Anesthetics, General ; Cell Membrane ; Cells, Cultured ; Chromosome Pairing ; Membrane Potentials ; Membranes ; Microscopy, Video ; Neurons ; Patch-Clamp Techniques ; Synaptic Transmission

According to the widely accepted concept that contraction of arterial smooth muscle is dependent on the Ca2+/calmodulin and protein kinase C(PKC) systems, it has been recently proposed that activation of these two systems in vascular smooth muscle cells has a bearing on the pathogenesis of cerebral vasospasm. However, most of the reported PKC inhibitors display a poor selectivity. In a rabbit "vasospasm" model, we tested the effect of a new PKC inhibitor(Bisindolylmaleimides; BIS) which has been known for a relatively high degree of selectivity, and also investigated the possible role of a inhibitor of Ca2+/calmodulin-dependent protein kinase(CAM kinase II inhibitor; KN-62). Finally, the vasodilating action of BIS was compared to KN-62. The basilar artery was visualized using transclival exposure, and its diameter monitored using videomicroscopy. Rabbit basilar artery was constricted in vivo by topical application of phorbol dibutyrate. Application of phorbol dibutyrate elicited an acute constriction, reducing arterial diameter to 46.5% of baseline diameter. Treatment with BIS (5micrometer) attenuated phorbol dibutyrate-induced vasoconstriction to 96.2% of baseline. Subsequently, application of oxyhemoglobin(oxy-Hb; 10 -4M) reduced vascular diameter to 68.5% of baseline. This vasospastic response was reversed by 91.4% or 81.3% using BIS(5micrometer) or KN-62(5micrometer), respectively. Combined applications of BIS and KN-62 to investigate the enhancing effect produced basilar arterial constriction of 94.9% of baseline. These findings demonstrate that BIS is a potent PKC inhibitor, and PKC system, rather than Ca2+/calmodulin system, appears to play a major role in the occurrence of cerebral vasospasm. Additionally, we suggest that combination of PKC with CAM kinase II inhibitor may be more useful therapeutic agents for treating cerebral vasospasm.
Basilar Artery* ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; Constriction* ; Microscopy, Video ; Muscle, Smooth ; Muscle, Smooth, Vascular ; Phosphotransferases ; Protein Kinase C* ; Protein Kinases* ; Vasoconstriction ; Vasospasm, Intracranial

To study the cleavage of neuron stem cells in time lapse image sequences and realize their features abstraction, identification and tracking, a precise segmentation algorithm that can preserve the shape of division cells is presented in this paper. The fuzzy threshold segmentation is based on Zadth's maximum entropy. The optimal parameters of the maximum fuzzy entropy are decided by genetic algorithm. Region merging and splitting of the under-segmentation objects of the result of fuzzy segmentation are realized by weighted distance transform, region labeling and some operations on morphology. By comparison with some results of fuzzy and hard segmentation, this algorithm can implement the precise segmentation that is necessary for some specified objects in automatic identification and tracking of neuron stem cells.
Algorithms ; Cell Culture Techniques ; methods ; Cell Division ; Computer Simulation ; Entropy ; Fuzzy Logic ; Humans ; Image Processing, Computer-Assisted ; Microscopy, Video ; methods ; Models, Biological ; Neurons ; cytology ; Stem Cells ; cytology

OBJECTIVES: The present study assessed the effect of trazodone on the cerebral hemodynamics of male Sprague-Dawley rats. METHOD: The changes of regional cerebral blood flow(rCBF) and pill arterial diameter were measured by laser-Doppler flowmetry and by a videomicroscopy, respectively. The changes in vascular tone and intracellular free Ca2+ concentration ([Ca2+]i) of isolated basilar artery were simultaneously measured using a small vessel myograph and a cation measurement system, respectively. RESULT: Both the rCBF and the pill arterial diameter were dose-dependently decreased by systemic administration of trazodone(0.3-10 mg/kg, i.v.), but not by topical application of trazodone(10-300 micrometer). Pretreatment with 5-HT(2A/2C) receptor antagonist(ketanserin or ritanserin, 1 mg/kg, i.v., respectively) significantly blocked the changes in rCBF induced by trazodone. m-Chlorophenylpiperazine(mCPP ; 0.1-3 mg/kg, i.v. or 5-500 micrometer topical), a major active metabolite of trazodone, also dose-dependently decreased the rCBF as well as the pial arterial diameter. The mCPP-induced decreases in rCBF were significantly blocked by ketanserin. Pretreatment with itraconazole(1 mg/kg, p.o.), a selective inhibitor of CYP3A4, a subfamily of cytochrome P450, markedly attenuated the trazodone-induced changes in rCBF. In an isolated rat basilar arterial strip loaded with fura-2/AM, mCPP(5-500 micrometer caused a vasoconstriction in association with increases in [Ca2+]i, in a concentration-dependent manner. Pretreatment with 1 micrometerketanserin strongly blocked the effects of mCPP on the vascular tone as well as on the [Ca2+]i, of rat basilar artery. CONCLUSION: These results suggest that trazodone decreases rCBF through stimulation of 5-HT(2A/2C) receptors by its active metabolite, mCPP.
Animals ; Basilar Artery ; Cytochrome P-450 Enzyme System ; Hemodynamics* ; Humans ; Ketanserin ; Laser-Doppler Flowmetry ; Male ; Microscopy, Video ; Rats* ; Rats, Sprague-Dawley ; Ritanserin ; Trazodone* ; Vasoconstriction