Whole-mount sections displaying microvascular and glandular structures in human uterus using multiphoton excitation microscopy

There has been considerable interest over many years in the precise structural relationships between microvessels and secretory glands in human endometrium. However, microcirculatory networks have rarely been studied in three-dimensions (3D) using modern computerised technologies, this has been partly due to the late arrival of suitable endothelial cell markers. This study was designed to develop a technique to visualize and to reveal the relationships between microvessels, their glandular environment and epithelial boundaries in 3D, using endometrium from human hysterectomy biopsies. Specimens were carefully selected from women with conditions unlikely to affect the microvascular networks. Monoclonal antibodies (mouse anti-human CD 34 and goat anti-mouse fluorescein (FITC)) were used to visualize the microvessels, and polyclonal antibodies (rabbit anti-human keratin and goat anti-rabbit tetramethylrhodamine (TRITC)) were used to visualize the glandular structures. The samples were studied with a Leica multiphoton system using a titanium–sapphire laser (excitation 800 nm with pulses in the 200 fs range) to obtain a stack of two-dimensional (2D) images to a minimal focus depth of 120 μm. The initial data sets acquired were volume rendered using the integrated software of the Leica system to produce 3D images. This software allowed for the acquisition of data sets from the microscope and for an observational morphological assessment to be made, but was limited in preparing the data for any quantitative analysis. The additional use of ImarisBasic 3.1 visualization software allowed for an observational morphological assessment but also included numerous tools for data manipulation.     

An ultrastructural study of microvascular inter-endothelial tight junctions in normal endometrium

OBJECTIVE: To investigate changes in tight junctions between microvascular endothelial cells in normal endometrium. STUDY DESIGN: A quantitative transmission electron microscopy study of changes in the number of tight junctions per microvessel, and widths and lengths of individual junctions at different phases of the menstrual cycle. RESULTS: Two types of tight junctions were defined ("open" and "closed") which varied in the degree of separation between apposed plasma membranes of endometrial endothelial cells. Tight junction density was greater in proliferative than secretory phases (p<0.02). The width and length measurements of individual tight junctions changed during menstruation. CONCLUSIONS: The two types of tight junctional contacts and the changes in width and density may reflect variation in structure and function between adjacent endothelial cells. These junctions may have importance in the processes of implantation and menstruation.     

Medical application of diffraction enhanced imaging in mouse liver blood vessels

Neovascularization is correlative with many processes of diseases, especially for tumor growth, invasion, and metastasis. What is more, these tumor microvessels are totally different from normal vessels in morphology. Therefore, observation of the morphologic distribution of microvessels is one of the key points for many researchers in the field. Using diffraction enhanced imaging (DEI), we observed the mirocvessles with diameter of about 40 μm in mouse liver. Moreover, the refraction image obtained from DEI shows higher image contrast and exhibits potential use for medical applications.

     

Histopathological analysis of a bladder cancer stalk observed on MRI

Papillary transitional cell carcinoma of the bladder has a loose connective tissue stalk. For staging of bladder cancer on magnetic resonance imaging (MRI), it is important to clearly separate the cancer from the bladder wall. It is possible to distinguish a stalk from the cancer by the difference of intensity on the using MRI. Sixteen stalks of 20 polypoid bladder tumors on any of the T(2)W(I), dynamic images and delayed enhanced images were demonstrated. Most of the stalks show lower signal intensity than the tumors on T(2)W(I), less enhancement on dynamic images and stronger enhancement on delayed enhanced images. The stalk consisted of fibrous connective tissue, capillary blood vessels, inflammatory cell infiltration and edema. This stalk extended from the bladder wall to the center of the tumor. Some of the superficial muscular bundles were pulled into the stalk. These histopathological findings were compatible with the patterns of signal intensities on MRI. The identification of the stalk of a polypoid tumor may be an important observation to exclude bladder wall invasion by tumor.     

Normal force exerted on vascular endothelial cells

Hemodynamic forces play an important role in the normal and pathological behavior of vascular endothelial cells as recent studies on the shear stress over the endothelium have shown. Based on computational investigation and scaling analysis, our study shows that the normal force contributes significantly to the total force on the endothelial cells even in large vessels. Therefore, our study suggests that the functions of endothelial cells are also affected by the normal forces exerted on them. The effects of the normal force are more pronounced for smaller vessels and/or less spread cells.     

Protein transfer to membranes upon shape deformation

Red blood cells, milk fat droplets, or liposomes all have interfaces consisting of lipid membranes. These particles show significant shape deformations as a result of flow. Here we show that these shape deformations can induce adsorption of proteins to the membrane. Red blood cell deformability is an important factor in several diseases involving obstructions of the microcirculatory system, and deformation induced protein adsorption will alter the rigidity of their membranes. Deformation induced protein transfer will also affect adsorption of cells onto implant surfaces, and the performance of liposome based controlled release systems. Quantitative models describing this phenomenon in biomaterials do not exist. Using a simple quantitative model, we provide new insight in this phenomenon. We present data that show convincingly that for cells or droplets with diameters upwards of a few micrometers, shape deformations induce adsorption of proteins at their interface even at moderate flow rates.     

Realignment of myocardial first-pass MR perfusion images using an automatic detection of the heart-lung interface

Magnetic resonance first-pass imaging of a bolus of contrast agent is well adapted to distinguish normal and hypoperfused areas of the myocardium. In most cases, the signal intensity-time curves in user defined regions of interest (ROI) are studied. As image acquisition is ECG-gated, the images are acquired at the same moment in the cardiac cycle, and the basic shape of the heart is similar from one view to the next. However, superficial respiratory motion can displace the heart in the short-axis plane. The aim of this study is to correct for the respiratory motion of the heart by performing an automatic realignment of the myocardial ROI based on a method tracking the movement of the lung-myocardium interface. Visual and quantitative analyses performed on 120 curves show a very good concordance between two automatic methods and the manual one.     

非圆小通道内水-空气垂直上升流动流型研究

微化工机械以及紧凑式换热器的发展,使非圆截面小通道在工程中获得大量应用,但现有文献针对非圆截面小通道内两相流动的研究报导屈指可数。本文采用可视化手段研究了水力直径分别为2．886 mm和1．443 mm的三角形截面并联小通道内水-空气垂直上升流动,表现气速0．1~100 m／s,表观水速0．1~6 m／s。根据观察和测量结果,总结得到了流型转变界限,并获得了典型流型图像。将本文的实验结果与前人的研究结果对比表明:通道的截面形状和水力直径均对非圆截面小通道内两相流型转变界限有显著的影响。     

Ultrastructural Evaluation of 585-nm Pulsed-Dye Laser-Treated Glottal Dysplasia

OBJECTIVE/HYPOTHESIS: To describe the ultrastructural changes occurring within pulsed-dye laser (PDL)-treated glottal tissues. STUDY DESIGN: Prospective. METHODS: Nine patients presenting with glottal dysplasia requiring biopsy to rule out microinvasive carcinoma were enrolled in this prospective study. At least two samples were obtained in each case: one from a PDL-treated area and another from a non-PDL-treated area (obtained from a nonphonatory region as an internal control). In some cases, a third sample was obtained from the junction between PDL- and non-PDL-treated areas. All samples were examined with light microscopy (H and E stain) and transmission electron microscopy. Observations were made of morphological changes within the epithelium, epithelial/ superficial lamina propria (SLP) junction, and the lamina propria of tissues treated with the PDL. Eight of nine patients were followed for a period of 9-25 months (mean, 18 months) with two recurrences that were retreated with awake-PDL and followed for an additional 8.3 and 9.5 months without recurrence. Vocal fold appearance returned to normal within 3-4 weeks posttreatment. RESULTS: Intraepithelial desmosome junctions were preferentially destroyed, and regional blood vessels were coagulated. The PDL consistently caused a separation of epithelial cells away from the basement membrane. CONCLUSIONS: The PDL allowed for both a surgical and a nonsurgical multimodality method for treatment of precancerous lesions with minimal effects on the SLP.     

M?ssbauer study of miniature vessels from the Sic��n burial site of Huaca Loro

Small handmade ceramic vessels are often found in large quantities in late pre-hispanic elite tombs on the north coast of Peru. These miniature vessels are of poor artistic and technologic qualities compared with other offerings found in tombs and have not received much attention. Our hypothesis is that these miniatures were made hastily by non-elite funeral attendants, which resulted in the observed formal and material variability. Here we report on the results of a systematic archaeological analysis of the shape and of archaeometric analyses by Mössbauer spectroscopy and XRD of the firing conditions of such vessels that were conducted to test the above hypothesis.     

Visualization of microvessels by angiography using inverse‐Compton scattering X‐rays in animal models

The fundamental performance of microangiography has been evaluated using the S‐band linac‐based inverse‐Compton scattering X‐ray (iCSX) method to determine how many photons would be required to apply iCSX to human microangiography. ICSX is characterized by its quasi‐monochromatic nature and small focus size which are fundamental requirements for microangiography. However, the current iCSX source does not have sufficient flux for microangiography in clinical settings. It was determined whether S‐band compact linac‐based iCSX can visualize small vessels of excised animal organs, and the amount of X‐ray photons required for real time microangiography in clinical settings was estimated. The iCSX coupled with a high‐gain avalanche rushing amorphous photoconductor camera could visualize a resolution chart with only a single iCSX pulse of ～3 ps duration; the resolution was estimated to be ～500 µm. The iCSX coupled with an X‐ray cooled charge‐coupled device image sensor camera visualized seventh‐order vascular branches (80 µm in diameter) of a rabbit ear by accumulating the images for 5 and 30 min, corresponding to irradiation of 3000 and 18000 iCSX pulses, respectively. The S‐band linac‐based iCSX visualized microvessels by accumulating the images. An iCSX source with a photon number of 3.6 × 10³–5.4 × 10⁴ times greater than that used in this study may enable visualizing microvessels of human fingertips even in clinical settings.     

Atomic force microscopy of Bacillus spore surface morphology

Bacillus spore surface morphology was imaged with atomic force microscopy (AFM) to determine if characteristic surface features could be used to distinguish between four closely related species; Bacillus anthracis Sterne strain, Bacillus thuringiensis var. kurstaki, Bacillus cereus strain 569, and Bacillus globigii var. niger. AFM surface height images showed an irregular topography across the curved upper surface of the spores. Phase images showed a superficial grain structure with different levels of phase contrast and significant differences in average surface morphologies among the four species. Although spores of the same species showed similarities, there was significant variability within each species. Overall, AFM revealed that spore surface morphology is rich with information, which can be used to distinguish a sample of about 20 spores from a similar number of spores of closely related species. Statistical analysis of spore morphology from a combination of amplitude and phase images for a small sample allows differentiation between, B. anthracis and its close relatives.     

Optical,nanostructural, and biophysical properties of Zn-induced changes in human erythrocyte membranes

We studied changes in the surface of erythrocyte membranes exposed to the action of zinc sulfate in the concentration range of 0.1–2.0 mM/l using methods of light scattering, spectrofluorimetry, and atomic force microscopy. Using the spectrofluorimetry method, we revealed a dose-dependent increase in the fluorescence intensity of a fluorescamine probe incorporated into erythrocyte membranes modified by zinc ions, which is indicative of an increase in the level of NH₂ groups on the cell surface. Using atomic force microscopy, we revealed changes in the surface topography of erythrocyte membranes exposed to the action of zinc sulfate in the concentration range of 0.1–2.0 mM/l. By performing a correlation analysis, we revealed that the correlation length of the autocorrelation function of the erythrocyte surface irregularity profile directly related to the fluorescence intensity of fluorescamine incorporated into erythrocyte membranes (r = 0.9, p < 0.05) modified by zinc ions. We showed that, in the zinc sulfate concentration range of 0.1–2.0 mM/l, zinc oxides form in erythrocyte membranes, which is confirmed by the appearance of an absorption band at 330–340 nm and by an increase in the light scattering. At more considerable concentrations, we identified absorption bands characteristic of zinc protein complexes in erythrocyte membranes. A considerable decrease in the elongation of the scattering indicatrix of erythrocyte membranes caused by luminescence correlates with the content of zinc proteins. Polarization measurements confirm the enhancement of the aggregation of protein complexes observed by the atomic force microscopy method. The proposed complex approach can be used in studies on the action of various abiotic factors on biological cells.     

Lymphocyte migration in the micro-channel of splenic sheathed capillaries in Chinese soft-shelled turtles,Pelodiscus sinensis

The structural characteristics of the splenic sheathed capillary were investigated using light microscopy and transmission electron microscopy (TEM). This study mainly focused on lymphocyte migration to the splenic white pulp via micro-channels in Chinese soft-shelled turtles, Pelodiscus sinensis. The results showed that the sheathed capillaries in the turtle spleen were high endothelial venule (HEV)-like vessels. These capillaries consist of micro-channels that facilitate lymphocyte migration to the splenic white pulp. The micro-channel is a dynamic structure comprising processes of endothelial cells, supporting cells, and ellipsoid-associated cells (EACs), which provides a microenvironment for lymphocyte migration. The pattern of lymphocyte migration in the micro-channel of the turtle spleen includes the following steps: (i) lymphocyte first adheres to the endothelium of the sheathed capillary, passes through the endothelial cells, and traverses through the basement membrane of the sheathed capillary; (ii) it then enters into the ellipsoid combined with supporting cells and EACs; and (iii) lymphocyte migrates from the ellipsoid to the periellipsoidal lymphatic sheath (PELS) via the micro-channel. This study provides morphological evidence for lymphocyte migration in the micro-channels of turtle spleens and also an insight into the mechanism of lymphocyte homing to the splenic white pulp of reptiles.     

Temporal mechanisms underlying recovery from forward masking in multielectrode-implant listeners

This paper describes a detailed study of recovery from forward masking in six users of the Nucleus-22 cochlear implant with a range of performance in speech-recognition tests. Recovery from a 300-ms-long pulse train presented at 1000 pps was found to be fastest in the poorer performers. The shape of the recovery function was found to be most strongly influenced by masker duration, suggesting that temporal integration plays a prominent role in recovery from forward masking. The recovery functions are reasonably well described by a sum of two exponentially decaying processes. Their relative weights depend on the amount of temporal integration occurring during the masker, and show strong intersubject variability. Nonmonotonicities sometimes observed in the recovery functions may be accounted for by considering the influence of neural adaptation.     

Distribution of chondroitin sulfate in human endometrium

Sulfated glycosaminoglycan (GAG) composition was characterized in the human endometrium during proliferative and secretory phases of the menstrual cycle. Sulfated GAGs were analyzed in endometrium tissue using metachromatic staining, biochemical analysis including electrophoresis before and after specific enzymatic or chemical degradations, and immunostaining with an antibody against chondroitin sulfate (CS). Our results showed that CS was the main sulfated GAG species detected, accompanied by small amounts of heparan sulfate and dermatan sulfate. CS was distributed overall the connective stroma, around arteriole vessels and glands, and there was no important difference in the immunostaining between the proliferative and secretory endometrium phases. Our findings extend previous observations on the GAG composition in the human endometrium providing new information regarding the tissue distribution and location of endometrial CS.     

Imaging of subcutaneous microcirculation vascular network by double correlation Optical Coherence Tomography

Spatial distribution of superficial blood vessels in human skin in vivo has been observed by using the double correlation Optical Coherence Tomography (OCT). To remove background noise, reduce the artifacts associated with patient motions and to increase the overall quality of the experimental OCT images an adaptive Wiener filtering technique has been employed. Fourier domain correlation has been subsequently applied to enhance spatial resolution of images of vascular network in human skin in vivo. Image processing has been performed on Graphics Processing Units (GPUs) utilizing Compute Unified Device Architecture (CUDA) framework in the frequency‐domain. This approach allows carrying out image processing in parallel significantly speeding up the computations. The presented results show that the double correlation method permits obtaining 2D/3D OCT images of subcutaneous microcirculation vascular network and its spatial distribution within the human skin with higher spatial resolution compare to the other OCT correlation‐based techniques developed earlier.     

Thermally Induced Magnetite–Haematite Transformation

Ceramic finds from the Inka workshops at Tambo Real and La Viña in the Leche Valley in northern Peru were studied by Mössbauer spectroscopy, thin section microscopy and X-ray diffraction. Sherds of Inka style vessels and of local style vessels can be distinguished by their shape, although local techniques appear to have been used in making both types. A reconstruction of the firing techniques by scientific studies of the ceramic material does not reveal a substantial difference in material or in the firing of both forms, although high firing temperatures were necessary to achieve sufficient stability of the large Inka style vessels. It cannot be decided whether the smaller local vessels were fired together with the Inka vessels or separately. Most of the variation in the maximum firing temperature can be explained with the normal temperature and atmosphere fluctuations in an open pit kiln.     

The motion artifact suppression technique (MAST) in magnetic resonance imaging: clinical results

The Motion Artifact Suppression Technique (MAST) is a method which uses a series of gradient echos that are computed to cancel velocity, acceleration and pulsatility components of involuntary motion in MR imaging. A total of 916 patient studies were performed over a nine month period using MAST sequences with a TE 40, 60, 80, 100, 120, and 26/112. There was considerable improvement in long TR, long TE images. Cerebrospinal fluid flow artifacts were reduced. Body and spine images had reduced flow and respiratory artifacts. Spin rephasing in blood vessels caused increase intraluminal signal. This might be useful for cardiovascular imaging.     

The resolution of complex spectral patterns by cochlear implant and normal-hearing listeners

The differences in spectral shape resolution abilities among cochlear implant (CI) listeners, and between CI and normal-hearing (NH) listeners, when listening with the same number of channels (12), was investigated. In addition, the effect of the number of channels on spectral shape resolution was examined. The stimuli were rippled noise signals with various ripple frequency-spacings. An adaptive 41FC procedure was used to determine the threshold for resolvable ripple spacing, which was the spacing at which an interchange in peak and valley positions could be discriminated. The results showed poorer spectral shape resolution in CI compared to NH listeners (average thresholds of approximately 3000 and 400 Hz, respectively), and wide variability among CI listeners (range of approximately 800 to 8000 Hz). There was a significant relationship between spectral shape resolution and vowel recognition. The spectral shape resolution thresholds of NH listeners increased as the number of channels increased from 1 to 16, while the CI listeners showed a performance plateau at 4-6 channels, which is consistent with previous results using speech recognition measures. These results indicate that this test may provide a measure of CI performance which is time efficient and non-linguistic, and therefore, if verified, may provide a useful contribution to the prediction of speech perception in adults and children who use CIs.