Split-spectrum amplitude-decorrelation angiography with optical coherence tomography.

Amplitude decorrelation measurement is sensitive to transverse flow and immune to phase noise in comparison to Doppler and other phase-based approaches. However, the high axial resolution of OCT makes it very sensitive to the pulsatile bulk motion noise in the axial direction. To overcome this limitation, we developed split-spectrum amplitude-decorrelation angiography (SSADA) to improve the signal-to-noise ratio (SNR) of flow detection.

SPINDLIN1 promotes cancer cell proliferation through activation of WNT/TCF-4 signaling.

SPINDLIN1, a new member of the SPIN/SSTY gene family, was first identified as a gene highly expressed in ovarian cancer cells. We have previously shown that it is involved in the process of spindle organization and chromosomal stability and plays a role in the development of cancer. Nevertheless, the mechanisms underlying its oncogenic role are still largely unknown.

Responses of peripheral blood flow to acute hypoxia and hyperoxia as measured by optical microangiography.

Oxygen availability is regarded as a critical factor to metabolically regulate systemic blood flow. There is a debate as to how peripheral blood flow (PBF) is affected and modulated during hypoxia and hyperoxia; however in vivo evaluating of functional PBF under oxygen-related physiological perturbation remains challenging. Microscopic observation, the current frequently used imaging modality for PBF characterization often involves the use of exogenous contrast agents, which would inevitably perturb the intrinsic physiologic responses of microcirculation being investigated.

Epimorphin promotes human hepatocellular carcinoma invasion and metastasis through activation of focal adhesion kinase/extracellular signal-regulated kinase/matrix metalloproteinase-9 axis.

Unlabelled: The high incidence rate of hepatocellular carcinoma (HCC) is mainly the result of frequent metastasis and tumor recurrence. Unfortunately, the underlying molecular mechanisms driving HCC metastasis are still not fully understood. It has been demonstrated that tumor stroma cells contribute to primary tumor growth and metastasis.

Optical microangiography provides an ability to monitor responses of cerebral microcirculation to hypoxia and hyperoxia in mice.

In vivo imaging of microcirculation can improve our fundamental understanding of cerebral microhemodynamics under various physiological challenges, such as hypoxia and hyperoxia. However, existing techniques often involve the use of invasive procedures or exogenous contrast agents, which would inevitably perturb the intrinsic physiologic responses of microcirculation being investigated. We report ultrahigh sensitive optical microangiography (OMAG) for label-free monitoring of microcirculation responses challenged by oxygen inhalation.

Role of epimorphin in bile duct formation of rat liver epithelial stem-like cells: involvement of small G protein RhoA and C/EBPβ.

Epimorphin/syntaxin 2 is a high conserved and very abundant protein involved in epithelial morphogenesis in various organs. We have shown recently that epimorphin (EPM), a protein exclusively expressed on the surface of hepatic stellate cells and myofibroblasts of the liver, induces bile duct formation of hepatic stem-like cells (WB-F344 cells) in a putative biophysical way. Therefore, the aim of this study was to present some of the molecular mechanisms by which EPM mediates bile duct formation.

Ultrahigh sensitive optical microangiography reveals depth-resolved microcirculation and its longitudinal response to prolonged ischemic event within skeletal muscles in mice.

The primary pathophysiology of peripheral arterial disease is associated with impaired perfusion to the muscle tissue in the lower extremities. The lack of effective pharmacologic treatments that stimulate vessel collateralization emphasizes the need for an imaging method that can be used to dynamically visualize depth-resolved microcirculation within muscle tissues. Optical microangiography (OMAG) is a recently developed label-free imaging method capable of producing three-dimensional images of dynamic blood perfusion within microcirculatory tissue beds at an imaging depth of up to ∼2 mm, with an unprecedented imaging sensitivity of blood flow at ∼4 μm∕s.

Highly sensitive imaging of renal microcirculation in vivo using ultrahigh sensitive optical microangiography.

Studying renal microcirculation and its dynamics is of great importance for understanding the renal function and further aiding the diagnosis, prevention and treatment of renal pathologies. In this paper, we present a potentially useful method to provide high-sensitive volumetric imaging of renal microcirculations using ultrahigh-sensitive optical microangiography (UHS-OMAG). The UHS-OMAG image system used here is based on spectral domain optical coherence tomography, which uses a broadband light source centered at 1300 nm with an imaging speed of 150 frames per second that requires ~6.

Label-free 3D optical microangiography imaging of functional vasa nervorum and peripheral microvascular tree in the hind limb of diabetic mice.

Diabetic neuropathy (DN) is, at least in part, associated with the functional attenuation of vasa nervorum, the microvascular structure of peripheral nerves. Microvascular imaging options for vasa nervorum still remain limited. In this work, Optical micro-angiography (OMAG), a volumetric, label-free imaging technique is utilized for characterizing, with high resolution, blood perfusion of peripheral nerve in diabetic mice.

In vivo optical imaging of revascularization after brain trauma in mice.

Revascularization following brain trauma is crucial to the repair process. We used optical micro-angiography (OMAG) to study endogenous revascularization in living mice following brain injury. OMAG is a volumetric optical imaging method capable of in vivo mapping of localized blood perfusion within the scanned tissue beds down to capillary level imaging resolution.

Label-free in vivo optical imaging of functional microcirculations within meninges and cortex in mice.

Abnormal microcirculation within meninges is common in many neurological diseases. There is a need for an imaging method that is capable of monitoring dynamic meningeal microcirculations, preferably decoupled from cortical blood flow. Optical microangiography (OMAG) is a recently developed label-free imaging method capable of producing 3D images of dynamic blood perfusion within micro-circulatory tissue beds at an imaging depth up to ∼2 mm, with an unprecedented imaging sensitivity to blood flow at ∼4 μm/s.

Label-free and highly sensitive optical imaging of detailed microcirculation within meninges and cortex in mice with the cranium left intact.

We demonstrate for the first time that the detailed blood flow distribution within intracranial dura mater and cortex can be visualized by an ultrahigh sensitive optical microangiography (UHS-OMAG). The study uses an UHS-OMAG system operating at 1310 nm with an imaging speed at 150 frames per second that requires approximately 10 s to complete one 3-D scan of approximately 2.5 x 2.

Epimorphin regulates bile duct formation via effects on mitosis orientation in rat liver epithelial stem-like cells.

Understanding how hepatic precursor cells can generate differentiated bile ducts is crucial for studies on epithelial morphogenesis and for development of cell therapies for hepatobiliary diseases. Epimorphin (EPM) is a key morphogen for duct morphogenesis in various epithelial organs. The role of EPM in bile duct formation (DF) from hepatic precursor cells, however, is not known.

Optical micro-angiography images structural and functional cerebral blood perfusion in mice with cranium left intact.

Alteration in regional cerebral blood flow (CBF) is the direct result of changes in neuronal activity. It is crucial to monitor the spatio-temporal characteristics of cerebro-vascular blood perfusion in the studies of cerebral diseases. Optical micro-angiography (OMAG) is a recently developed imaging technique capable of resolving 3D distribution of dynamic blood perfusion at a capillary level resolution within microcirculatory beds in vivo.

Doppler optical microangiography improves the quantification of local fluid flow and shear stress within 3-D porous constructs.

Traditional phase-resolved Doppler optical coherence tomography (DOCT) has been reported to have potential for characterizing local fluid flow within a microporous scaffold. In this work, we apply Doppler optical microangiography (DOMAG), a new imaging technique developed by combining optical microangiography (OMAG) with a phase-resolved method, for improved assessment of local fluid flow and its derived parameters, shear stress, and interconnectivity, within highly scattering porous constructs. Compared with DOCT, we demonstrate a dramatic improvement of DOMAG in quantifying flow-related properties within scaffolds in situ for functional tissue engineering.

Potential of optical microangiography to monitor cerebral blood perfusion and vascular plasticity following traumatic brain injury in mice in vivo.

Optical microanglography (OMAG) is a recently developed imaging modality capable of volumetric imaging of dynamic blood perfusion, down to capillary level resolution, with an imaging depth up to 2.00 mm beneath the tissue surface. We report the use of OMAG to monitor the cerebral blood flow (CBF) over the cortex of mouse brain upon traumatic brain injury (TBI), with the cranium left intact, for a period of two weeks on the same animal.

Doppler optical coherence tomography imaging of local fluid flow and shear stress within microporous scaffolds.

Establishing a relationship between perfusion rate and fluid shear stress in a 3D cell culture environment is an ongoing and challenging task faced by tissue engineers. We explore Doppler optical coherence tomography (DOCT) as a potential imaging tool for in situ monitoring of local fluid flow profiles inside porous chitosan scaffolds. From the measured fluid flow profiles, the fluid shear stresses are evaluated.

Primary high-dose murine norovirus 1 infection fails to protect from secondary challenge with homologous virus.

Human noroviruses in the Caliciviridae family are the major cause of nonbacterial epidemic gastroenteritis worldwide. Primary human norovirus infection does not elicit lasting protective immunity, a fact that could greatly affect the efficacy of vaccination strategies. Little is known regarding the pathogenesis of human noroviruses or the immune responses that control them because there has previously been no small-animal model or cell culture system of infection.

Type I and type II interferons inhibit the translation of murine norovirus proteins.

Human noroviruses are responsible for more than 95% of nonbacterial epidemic gastroenteritis worldwide. Both onset and resolution of disease symptoms are rapid, suggesting that components of the innate immune response are critical in norovirus control. While the study of the human noroviruses has been hampered by the lack of small animal and tissue culture systems, our recent discovery of a murine norovirus (MNV) and its in vitro propagation have allowed us to begin addressing norovirus replication strategies and immune responses to norovirus infection.

RhoA promotes differentiation of WB-F344 cells into the biliary lineage.

When cultured on Matrigel, liver precursor epithelium WB-F344 cells could be induced to differentiate into biliary cells in which RhoA expression was upregulated. To further investigate the role of RhoA in WB cell differentiation initiated by Matrigel treatment, we constructed constitutively active RhoA-expressing vectors and stably transfected them into WB-F344 cells. Accompanying upregulation of biliary lineage markers and morphological changes, cells with ectopically active RhoA expression were found to form bile-duct-like structures even without Matrigel treatment.

[Spectroscopic evaluation of time-resolved fluoroimmunoassay].

The lanthanide trivalence ion and its chelates are used for marking substance in Time-Resolved Fluorescence Immunoassay (TRFIA), marking protein, hormone, antibody, nucleic acid probe or biologic alive cell, to measure the concentration of the analysis substance inside the reaction system with time-resolved fluorometry after the reaction system occurred, and attain the quantitative analysis's purpose. TRFIA has therefore become a kind of new and more sensitive measurement method after radioisotope marking, enzymatic marking, chemiluminescence, electrochemiluminescence, primarily depending on the special physics and chemistry characteristics of lanthanide trivalence ion and its chelates. In this paper, the result of spectroscopic evaluation of europium trivalence ion and its chelate, and the principle of time-resolved technology and fluorescence-enhanced technology are reported.

Effect of low-power He-Ne laser irradiation on rabbit articular chondrocytes in vitro.

Background And Objectives: In the orthopaedic field, the repair of articular cartilage is still a difficult problem, because of the physiological characters of cartilaginous tissues and chondrocytes. To find an effective method of stimulating their regeneration, this in vitro study focuses on the biostimulation of rabbit articular chondrocytes by low-power He-Ne laser.

Study Design/materials And Methods: The articular chondrocytes isolated from the cartilage of the medial condyle of the femur of the rabbit were incubated in DMEM/HamF(12) medium.