Fine Capillaries Research Articles

X-ray and SEM Observations of Smectic A Phase and Dried Gel Fibers Formed in a Fine Capillary

Abstract Gel fibers of 2-oxochromen-6-yl 4-(S)-(2,6-dimethylheptyloxy) and 4-(S)-(3,7-dimethyloctyloxy)benzoates in cyclohexane were observed to grow along the surface of wall in a fine capillary. The structure of the oriented fibers was characterized by SEM and X-ray diffraction measurements, and the fiber structure was compared with the layer one in the smectic A phase.

OPTICAL/DIGITAL CHROMOENDOSCOPY DURING COLONOSCOPY USING NARROW‐BAND IMAGING SYSTEM

This review is regarding the narrow‐band imaging (NBI) system which has been developed at National Cancer Center Hospital East, Japan. The technology of the NBI system is based on modifying the spectral features by narrowing the bandwidth of spectral transmittance using various optical filters. The NBI system consists of three filters, 415–30 nm, 445–30 nm, and 500–30 nm, which are used as observing the fine capillaries in the superficial mucosa is essential to identify gastrointestinal neoplasms. The NBI system has been in development since 1999 and the first report of it's efficacy for gastrointestinal tract use was reported in 2001. In our pilot study, the NBI system may be sufficient to differentiate hyperplastic polyp from adenomatous polyp, and to visualize neoplasia with image processing in real‐time during colonoscopy without the need for dye spraying. Herein, we propose the term ‘optical/digital chromoendoscopy’ using the NBI system and hope that this instrument will become standard endoscopy for in the 21st century. To estimate the feasibility and efficacy of using the NBI system for surveillance or screening examination, randomized control trials should be conducted in the future.

Stromal cells in hemangioblastoma: Neuroectodermal differentiation and morphological similarities to ependymoma

The histogenesis of stromal cells in hemangioblastoma is inconclusive despite a long-term controversy. An immunohistochemical and ultrastructural study was conducted for 17 cases of cerebellar hemangioblastoma. A wide range of immunohistological markers, targeting epithelial, mesenchymal, endothelial and neuroectodermal tissues, was used. In all cases, the microscopic hallmark characterizing hemangioblastomas, that is, lipid-containing stromal cells and a fine capillary network, known as a reticular variant, was noted. Stromal cells showed a variable immunoreactivity for neuroectodermal markers, such as S-100 protein, CD56, CD57, CD99, and neuron-specific enolase. This result, in conjunction with the absence of immunoreactivity for epithelial, mesenchymal, and endothelial markers, likely suggests neuroectodermal differentiation of stromal cells. In three cases, another component, known as a cellular variant, where epithelioid tumor cells were arranged in nests encircled by capillaries and/or in pseudorosette-like structures, was noted. Glial fibrillary acidic protein-immunoreactivity, which was totally absent in cases only showing the reticular pattern, was noted in two of them, suggesting a distinctive sign of glial differentiation in a proportion of hemangioblastomas. Ultrastructurally, microvilli-like projections in intracytoplasmic vacuoles were demonstrated in stromal cells. This result, taken together with the neuroectodermal hypothesis of stromal cells, suggests that hemangioblastomas may occasionally exhibit morphological similarities to ependymomas.

Hematopoietic cells regulate the angiogenic switch during tumorigenesis

AbstractHematopoietic cells (HCs) promote blood vessel formation by producing various proangiogenic cytokines and chemokines and matrix metalloproteinases. We injected mouse colon26 colon cancer cells or human PC3 prostate adenocarcinoma cells into mice and studied the localization of HCs during tumor development. HCs were distributed in the inner tumor mass in all of the tumor tissues examined; however, the localization of HCs in the tumor tissue differed depending on the tumor cell type. In the case of colon26 tumors, as the tumor grew, many mature HCs migrated into the tumor mass before fine capillary formation was observed. On the other hand, although very few HCs migrated into PC3 tumor tissue, c-Kit+ hematopoietic stem/progenitor cells accumulated around the edge of the tumor. Bone marrow suppression induced by injection of anti–c-Kit neutralizing antibody suppressed tumor angiogenesis by different mechanisms according to the tumor cell type: bone marrow suppression inhibited the initiation of sprouting angiogenesis in colon26 tumors, while it suppressed an increase in the caliber of newly developed blood vessels at the tumor edge in PC3 tumors. Our findings suggest that HCs are involved in tumor angiogenesis and regulate the angiogenic switch during tumorigenesis.

Evaluation of capillary pore size characteristics in high-strength concrete at early ages

The quantitative scanning electron microscope-backscattered electron (SEM-BSE) image analysis was used to evaluate capillary porosity and pore size distributions in high-strength concretes at early ages. The Powers model for the hydration of cement was applied to the interpretation of the results of image analysis. The image analysis revealed that pore size distributions in concretes with an extremely low water/binder ratio of 0.25 at early ages were discontinuous in the range of finer capillary pores. However, silica-fume-containing concretes with a water/binder ratio of 0.25 had larger amounts of fine pores than did concretes without silica fume. The presence of larger amounts of fine capillary pores in the concretes with silica fume may be responsible for greater autogenous shrinkage in the silica-fume-containing concretes at early ages.

Narrow Band Imaging Endoscopy for the Detection of Dysplastic and Non Dysplastic Barrett's Esophagus

The distribution of metaplastic (IM) and dysplastic epithelium within the Barrett's esophagus (BE) segment is patchy requiring random biopsies. The use of new techniques to identify these high yield areas would be helpful.The sequential lighting method in video endoscopes have a rotation disk with RGB (red,green,blue) optical filters in front of a white light source (xenon lamp). Narrow Band Imaging (NBI) is a novel technique which changes these optical filters to spectral narrow band filters. The penetration depth of light is dependent on its wavelength with visible blue light penetrating only superficial areas of the tissue. Therefore, use of blue light with the help of a special NB filter (415 nm, 445 nm, 500 nm) will enable imaging of the superficial tissue structures. AIM: To study the clinical utility of NBI endoscopy in pts with suspected BE. METHODS: Patients suspected with BE were studied with a standard magnification endoscope (Olympus GIF 240Z,115×) using a NBI light source. NBI endoscopy provided a striking contrast between the squamous and columnar mucosa in the distal esophagus without dye spraying. Specific capillary and mucosal patterns within the BE segment were identified, biopsied and read by pathologists blinded to endoscopic findings. RESULTS: 51 patients with a mean age of 64 years (range: 43-85 yrs) and a mean BE length of 3.5 cms (range: 0.5-16 cms) have been studied using NBI. 24 patients had IM without dysplasia,10 had low grade dysplasia (LGD), 9 had high grade dysplasia (HGD) and 8 without IM/dysplasia. All patients with IM without dysplasia had a fine capillary pattern showing a normal size, shape and distribution of small blood vessels and a ridge/villous mucosal pattern; whereas all 9 HGD patients had an abnormal capillary pattern- increased number, tortous, dilated, corkscrew type small blood vessels. All except 1 LGD patient had a similar pattern as IM. The sensitivity and specificity of the ‘normal capillary pattern’ to rule out HGD were 97.8% and 100% respectively; whereas it's sensitivity and specificity to detect non dysplastic tissue were 100% and 53% respectively. All long BE and 71% of short BE patients were identified with NBI. CONCLUSIONS: By changing the spectral feature of the observation light, NBI endoscopy provides a high quality and sharp contrast image of the BE segment without using dye spray (chromoscopy). It also provides a detailed image of the capillary and mucosal patterns in BE patients with a high accuracy for the detection of dysplastic and non dysplastic tissue.

Analysis of cement pastes and mortars by a combination of backscatter-based SEM image analysis and calculations based on the Powers model

Formation of microstructure in cement pastes and mortars were quantitatively analyzed by the SEM-BSE image analysis. Effects of water/cement ratio and of the addition of mineral admixtures on the contents of unhydrated cement particles and pores were discussed. The proportions of each phase obtained by the analyses were compared with proportions calculated on the Powers model. It was found from comparisons that the volume fractions of the residual cement and pores obtained by the image analysis did not contradict those estimated from the Powers model. Lower water/cement ratio pastes and those undergoing pozzolanic reaction showed less fine capillary pores. It was also found that large capillary pores still remained in the mixtures at long ages. The gel/space ratio in the Powers and Brownyard equation was calculated from the phase constituents determined by the image analysis. For mortars without mineral admixture, the gel/space ratio by the image analysis could be related to the strength.

Histology and Morphometrics of the epidermis of the fins and sucking disc of the mudskipper,Periophtholmus modestus(Pisces, Gobiidae)

The epidermis of the mudskipper, Periophthalmus modestus, consists of three layers‐ the outermost layer, middle layer and stratum germinativum. Extensive fine blood capillaries are present near the superficial layer of epidermis and outermost layer in five fins and a sucking disc. The diffusion distance between the vascular capillaries and the surface of epidermis ranged from 3.6 to 10.9 μm: 3.6 μm in the sucking disc, 10.9 μm in the anal fin and 4.6 to 5.0 μm in the two dorsal fins. Rate of the surface area of respiratory epithelium, the surface area of the fine blood capillaries occupied per surface area of epidermis in 0.1 mm, is 3.7 to 4.4% in two dorsal fins and 1.1% in the anal fin. The middle layer is simpler in structure consisting of small or voluminous cells swollen by epidermal cells, and this layer appeared web‐like. Well‐developed lymphatic spaces containing lymphocytes existed in the stratum germinativum. The five fins and sucking disc had no epidermal glands.

Focusing of MeV ion beams by means of tapered glass capillary optics

We present evidence of the focusing effects of fine glass capillary optics for MeV He ion beams. The glass capillary optics are formed by a puller as to have inlet diameters of about 1 mm and outlet diameters of submicrons. The total length of the optics is about 50 mm. Impingent MeV ions to such optics are reflected by the inner wall several times, in a very similar process to the so-called surface channeling. The majority of incident ions are lost by the dechanneling, or large-angle scattering process, however, a part of them, actually about 1% more or less, is emitted through the outlet without significant energy loss. Compared with the conventional micro-ion beam facilities, the present method is certainly simple and lowcost, thus providing an easy method of submicron Rutherford backscattering spectrometry or particle induced x-ray emission analyses. In addition, if the ion species are extended to heavier elements, the present method provides versatile maskless ion implantation techniques.

Fine Needle Capillary Sampling of Eyelid Masses

To study the cytomorphology of eyelid tumors, correlate it with histopathology and determine the diagnostic accuracy of fine needle capillary (FNC) sampling (nonaspiration) in the evaluation of lid tumors. A prospective study of 70 cases of eyelid masses carried out using FNC, with confirmation by histology in 66 cases and peripheral blood smear and bone marrow examination in 3. Histology was not done in 1 case, and 11 cases were inadequate on cytology. The diagnostic accuracy of cytology was 94.73%, and false negativity was 5.17%. The ages of the patients ranged from 3 to 75 years, with a mean of 40.4. The male/female ratio was nearly equal (37:33). The upper eyelid was affected in 45 cases and lower lid in 25 cases. The right eye was affected in 35 cases, left eye in 34 cases and both eyes in 1 case. Fifteen benign, 35 malignant and 9 infectious/inflammatory lesions were encountered, with 11 inadequate smears. FNC sampling is an effective method of sampling eyelid tumors because it causes little discomfort to the patient and allows the operator to maintain better control over the procedure. A distinction between inflammatory, benign and malignant lesions and between the types of malignant tumors can be made.

Structure and Histochemistry of the Skin of a Torrent Catfish, Liobagrus mediadiposalis

The epidermis of the torrent catfish, Liobagrus mediadiposalis, consists of three layers: the outermost layer, middle layer and stratum germinativum. The epidermis consists of two types of skin glands, small mucus cell and voluminous club cell. The unicellular mucus cell contains acid sulfomucins (some sialomucins) and the club cell, sometimes binucleate, is proteinaceous. Well-developed vascularization is one of the characteristics of epidermis of L. mediadiposalis. Well-developed lymphatic spaces contain lymphocytes in the epidermis. The dermis lacks scales and consists mostly of a thick, dense connective tissue; its superficial region just below the basal membrane is supplied with fine blood capillaries. These histological features of the skin in L. mediadiposalis are consistent with that required for cutaneous respiration.

Mechanical response of sediments to bubble growth

Modeling the process of bubble growth in sediments requires an understanding of the physics that controls bubble shape and the interaction of the growing bubble with the sediment. To acquire this understanding we have conducted experiments in which we have injected gas through a fine capillary into natural and surrogate sediment samples and have monitored pressure during bubble growth to provide information about stress and strain. In gas injection studies with natural sediment samples, we have observed two modes of bubble growth behavior. One of these modes, characterized by a saw-tooth record of pressure as the bubble grows, is consistent with fracture of the medium. Observations indicate that bubble growth by fracture should correspond to bubbles that are coin- or disk-shaped. This shape is confirmed in observations of bubbles in natural sediments and in our studies of bubble injection into gelatin, a surrogate sediment material. Interpretation of the stress–strain results for bubble growth also required that we measure Young’s modulus, E. The measurements show E to be near 0.14 MN m 2, which differs by more than 4 orders of magnitude from values that have been reported in the literature. Our measurements of E give substantially better estimates of bubble shape than are predicted using the literature values. Our data are interpreted with linear elastic fracture mechanics (LEFM) which predicts that the critical pressure for bubble growth will depend on the bubble volume, V raised to the −1/5 power. While evidence of substantial heterogeneity in sediment properties is apparent in our results, this V −1/5 dependence is confirmed. Through application of LEFM theory, we have determined the critical stress intensity factor, K 1c, a material property and the principal determinant of bubble shape and growth by fracture. Our values of K 1c range from ∼2.8×10 −4 MN m −3/2 to ∼4.9×10 −4 MN m −3/2 for our natural sediment samples from Cole Harbor, Nova Scotia. We have also estimated the critical stress intensity factor for Eckernförde Bay samples by analyzing published images of natural bubbles. The K 1c obtained in this way is similar to our Cole Harbor results and is ∼5.5×10 −4 MN m −3/2.

Structure of the skin of an air‐breathing mudskipper, Periophthalmus magnuspinnatus

The epidermis of the mudskipper Periophthalmus magnuspinnatus consisted of three layers: the outermost layer, middle layer and stratum germinativum. Extensive vascular capillary networks were present near the superficial layer of epidermis and outermost layer. The diffusion distance between the vascular capillaries and the surface of epidermis was c. 1.5 ± 0.9μm. The middle layer consisted of small or voluminous cells swollen by epidermal cells. Due to the swollen cells, the thickness of the epidermis increased and the epidermis appeared web‐like. The swollen cells contained tonofilaments, lucent contents and desmosomes. Fine blood capillaries were also discernible in this layer. Well‐developed lymphatic spaces containing lymphocytes existed in the stratum germinativum. Numerous blood capillaries were present under the basement membrane. The dermis consisted of a stratum laxum and stratum compactum, and there was a definite area with acid mucopolysaccharides and a small scale in the stratum laxum. The skin had an epidermal pigment cell, dendritic melanophores (‐cytes) containing melanin granules within their cytoplasm, and two kinds of dermal pigment cells, melanophores and colourless pigments containing reflecting platelets.

Fibroblast Growth Factor 18 Influences Proximal Programming during Lung Morphogenesis

The structure and functions of the airways of the lung change dramatically along their lengths. Large-diameter conducting airways are supported by cartilaginous rings and smooth muscle tissue and are lined by ciliated and secretory epithelial cells that are involved in mucociliary clearance. Smaller peripheral airways formed during branching morphogenesis are lined by cuboidal and squamous cells that facilitate gas exchange to a network of fine capillaries. The factors that mediate formation of these changing cell types and structures along the length of the airways are unknown. We report here that conditional expression of fibroblast growth factor (FGF)-18 in epithelial cells of the developing lung caused the airway to adopt structural features of proximal airways. Peripheral lung tubules were markedly diminished in numbers, whereas the size and extent of conducting airways were increased. Abnormal smooth muscle and cartilage were found in the walls of expanded distal airways, which were accompanied by atypically large pulmonary blood vessels. Expression of proteins normally expressed in peripheral lung tubules, including SP-B and pro-SP-C, was inhibited. FGF-18 mRNA was detected in normal mouse lung in stromal cells surrounding proximal airway cartilage and in peripheral lung mesenchyme. Effects were unique to FGF-18 because expression of other members of the FGF family had different consequences. These data show that FGF-18 is capable of enhancing proximal and inhibiting peripheral programs during lung morphogenesis.

Thermoelectron-enhanced micrometer-scale plasma generation

The use of thermoelectrons allowed easy generation of a micrometer-scale very high-frequency plasma (thermoelectron-enhanced micrometer-scale plasma) in a fine capillary, with an inner diameter of approximately 120 μm. A tungsten wire, whose diameter was 25 μm, inserted into the region was used to provide thermoelectrons. Approximately 5 W of power was sufficient to sustain this plasma. The plasma was very stable and the discharge continued for at least 60 min.

X-ray fluorescence beamline at the LNLS: Current instrumentation and future developments (abstract)

The x-ray fluorescence (XRF) beamline, constructed at the Brazilian National Synchrotron Radiation Laboratory (LNLS-http://www.lnls.br), has been operating for the external users since August of 1998 (C. A. Pérez et al., Proc. of the European Conference on Energy Dispersive X-Ray Spectrometry, Bologna, Italy, 1998, pp. 125–129). The synchrotron source for this beamline is the D09B (15°) dipole magnet of the LNLS storage ring. Two main experimental setups are mounted at the XRF beamline. One consists of a high vacuum chamber adapted to carry out experiments in grazing excitation conditions. This allows chemical trace and ultratrace element determination on several samples, mainly coming from environmental and biological sciences. Another setup consists of an experimental station, operated in air, in which x-ray fluorescence analysis with spatial resolution can be done. This station is equipped with a fine conical capillary, capable of achieving 20 μm spatial resolution, and with an optical microscope in order to select the region of interest on the sample surface. In this work, the main characteristic of the beamline, experimental stations as well as the description of some new experimental facilities will be given. Future development in the instrumentation focuses on an appropriate x-ray optic to be able to carry out chemical trace analysis of light elements using the total x-ray fluorescence technique. Also, chemical mapping below 10 μm spatial resolution, while keeping high flux of photon on the sample, will be achieved by using the Kirkpatrick–Baez x-ray microfocusing optic.

Comparative Study of Fine Needle Aspiration and Fine Needle Capillary Sampling of Thyroid Lesions

To investigate whether fine needle capillary (FNC) sampling gives quantitatively and qualitatively superior cytologic material as compared to the conventional technique of fine needle aspiration (FNA) when performed by a single aspirator. Cross-sectional diagnostic test evaluation study. FNA and FNC were performed by a single operator on 200 diffuse and nodular thyroid lesions. A statistically significant difference in favor of FNC was observed for the parameter amount of cellular material. For the rest of the parameters--background blood or clot, degree of cellular degeneration, degree of cellular trauma and retention of architecture--the average score favored FNC but was not statistically significant--i.e., smears prepared from FNC displayed cellular material that was more concentrated, less damaged and less likely to be obscured by blood. Although FNC sampling was diagnostic in a greater number of cases than FNA sampling, this study did not prove a clear superiority of FNC over FNA. Until greater experience shows clear sampling superiority of FNC alone, rather than performing only FNA in diffuse or nodular thyroid lesions, incorporating FNC into the second puncture will definitely improve the quality and quantity of material at the patient's first visit.

1344 2 つの狭窄部を持つ毛細血管内における好中球の流動特性

1344 2 つの狭窄部を持つ毛細血管内における好中球の流動特性

Transient Electrokinetic Flow in Fine Capillaries

The transient response of electrolyte solutions in a narrow capillary tube or slit to a step change in the applied electric field and/or pressure gradient is analytically studied. The electric double layer adjacent to the charged capillary wall may have an arbitrary thickness relative to the capillary radius. The electrostatic potential distribution on a cross section of the capillary is developed by solving the Poisson–Boltzmann equation, and the fluid velocity profile evolving with time after the external field is imposed is obtained from the analytical solution of a modified Navier–Stokes equation. Closed-form formulas for the transient flow rate, electro-osmotic velocity, electric current, and streaming potential in the capillary are also derived as functions of relevant parameters. The results demonstrate that the behavior of the transient electrokinetic flow in a capillary tube and in a capillary slit is similar; however, the rate of evolution of the flow in a tube with time is faster by a factor of about 2 than that in a slit with its half thickness equal to the tube radius.

Ultra-thin layer chromatography (UTLC) — A new dimension in thin-layer chromatography

Miniaturization is general trend in modern analytical methods, with the main targets of increasing sensitivity, shortening analysis times drastically, and reducing the quantity of consumables per analysis. In planar chromatography a first step in this direction was the development of modern high-performance TLC (HPTLC). Compared with conventional TLC, the layers are characterized by smaller adsorbent material particle sizes and a slight reduction in layer thickness. A major final step in the direction of miniaturized planar chromatography are the new ultra-thin layers. In contrast with those on TLC and HPTLC plates, these layers are no longer based on granular adsorbents, but have a monolithic structure based on a silica gel matrix. This means there are no longer separate particles, as in TLC and HPTLC. Furthermore, no binder is needed to fix the layer on the glass plate. To be suitable for chromatographic purposes, the monolithic silica gel of these new ultra-thin layers has meso- and macro pores, with fine capillaries penetrating the layer. The layer thickness of approximately 10 μm is considerably less than that of conventional TLC and HPTLC layers. The exciting properties of these new UTLC silica gel plates, especially their selectivity and separation efficiency, are demonstrated by separations of steroids, pesticides, and some dyestuffs.