Coiled Vessels Research Articles

Dermatoscopic features of pigmented intraepidermal carcinoma on the head and neck.

Pigmented intraepidermal carcinoma is characterized by dermatoscopic dots and structureless areas, including dots in linear arrangement and by coiled vessels. There are no studies describing the dermatoscopic features of pigmented intraepidermal carcinoma on the head and neck. We aim to characterize the clinical and dermatoscopic appearance of this entity. We retrospectively analyzed 79 cases of pigmented intraepidermal carcinoma on the head and neck. Pigmented intraepidermal carcinoma on the head and neck was characterized dermatoscopically by multiple colors (98.7%, n=78), pigmented circles (48.1%, n=38), white circles (17.7%, n=14), angulated lines (41.8%, n=33) and structureless areas (86.1%, n=68). Dots in linear arrangement were present in 13.9% (n=11). Coiled vessels were present in 7.6% (n=6), the dominant vessel type being prominent serpentine vessels (29.2%, n=23), thicker and/or redder in color than surrounding vessels, most being in the angular arrangement of the dermal plexus (24.1%, n=19). Pigmented intraepidermal carcinoma on the head and neck differs from current published descriptions of pigmented intraepidermal carcinoma, reaching statistical significance with a lower incidence of coiled vessels and a higher incidence of pigmented circles, with evident similarities to pigmented actinic keratosis at that location.

Assessment of 5-Aminolaevulinic Acid Photodynamic Therapy (ALA-PDT) in Chinese patients with actinic keratosis: Correlation of dermoscopic features with histopathology.

The study examines the changes in dermoscopic features of actinic keratosis (AK) after photodynamic therapy, and delineates the association between AK dermoscopic and histopathological findings. A total of 21 patients (23 lesions) with pathologically confirmed actinic keratosis who received 5-aminolaevulinic acid (ALA) photodynamic therapy (ALA-PDT) were enrolled. The numbers of PDT treatments were: 1, n=1; 2, n=2; 3, n=10; 4, n=6; 5, n=2; 6, n=2). The dermoscopic features before and after the PDT were compared. There were statistically significant decreases in the positive rates of dermoscopic features including scales (P<0.001), follicular plugs with whitish halo (P=0.013), and red pseudonetwork (P=0.022) among patients treated with ALA-PDT. Dermoscopic feature was significantly associated with pathological grade (P<0.001). Histopathological hyperkeratosis was significantly associated with dermoscopic red pseudonetwork (P=0.034) and wavy vessel (P=0.005). Parakeratosis was associated with wavy vessels (P=0.001). For vascular hyperplasia in dermal papillae, the significant correlates included scales (P=0.011), follicular plugs with whitish halo (P=0.011), red pseudonetwork (P<0.001); coiled vessels (P=0.003) and rosette sign (P=0.004). Wavy vessels was the only feature correlating keratosis pilaris (P=0.003). The findings of the present study support dermoscopy as having potential to be useful for diagnosing and monitoring of actinic keratosis.

Vascular Features of Nail Psoriasis Using Dynamic Optical Coherence Tomography

Background: Nail psoriasis is a painful and disfiguring nail disease that often leads to invasive biopsies. Dermoscopy of the hyponychium can be useful in the diagnosis showing twisted coiled vessels. Structural features of nail psoriasis have been described with optical coherence tomography (OCT). Objectives: To investigate vascular features of nail psoriasis using dynamic OCT. Methods: This was an observational, prospective, controlled study in which psoriasis patients with psoriatic nail changes and healthy control patients underwent OCT imaging of the distal nail plate and proximal nail fold. Vertical and horizontal OCT images were analyzed to describe structural and vascular features and to quantify blood flow at depth. Results: Sixteen psoriatic nails and 16 control nails were included. Psoriatic nails had significantly increased blood flow in the proximal nail fold at depths of 0.72 mm (p = 0.035) and 0.76 mm (p = 0.027). Nail thickness was significantly greater in psoriatic nails compared to control nails (p = 0.0016). Compared to control nails, psoriatic nails had dilated, disorganized blood vessels superficially in the proximal nail fold. Limitations: The main limitation of our study is the relatively small sample size. Conclusions: OCT can identify structural and vascular features specific to nail psoriasis.

Vacuum generation by hydrogen permeation to atmosphere through austenitic and nickel-base-alloy vessel walls at temperatures from 573 K to 773 K

Abstract The permeation of hydrogen through metals is of great concern in hydrogen containment systems. In this study, hydrogen contained in seamless coiled tube vessels made of SUS 316L and Inconel 625 permeated the vessel walls at temperatures from 573 K to 773 K, and the decreasing interior pressure of the vessels was monitored for an extended period to characterize the behavior of the pressure change. It was found that the pressure became lower than the surrounding atmospheric pressure, and the vessels reached a vacuum. Hydrogen permeabilities through SUS 316L and Inconel 625 were determined from the pressure drop measurements. In order to ensure the reliability of the measurements, the permeabilities were also determined with a gas chromatograph that measured the concentration of hydrogen completely permeating the vessel wall. The permeabilities obtained with the two methods were in good agreement with each other. The pressure drop behavior was compared to, and found to be consistent with, theoretical calculations performed using the obtained permeabilities based on Fick’s law of diffusion.

Dermatoscopy of pigmented Bowen's disease

Pigmented Bowen's disease is not well characterized. To characterize the clinical and dermatoscopic appearance of pigmented Bowen's disease. We performed a retrospective analysis of 52 consecutive cases of pigmented Bowen's disease. Of 951 histopathologically verified cases of Bowen's disease that underwent biopsy during the study period, 52 (5.5%) were pigmented. Dermatoscopically pigmented Bowen's disease is typified by a pattern of dots and/or structureless zones. In 21.2% (n=11), we observed brown or gray dots arranged in a linear fashion. Vessels were identified in 67.3% of lesions with a predomination of coiled vessels. A linear arrangement of vessels was seen in 11.5%. Conclusions are limited by the fact that this was a retrospective, uncontrolled study. Pigmented Bowen's disease has a characteristic dermatoscopic pattern. Linear arrangement of brown and/or gray dots and/or coiled vessels is a specific clue to pigmented Bowen's disease.

Quantitative Doppler measures in coiled vessels: investigation on excised umbilical veins

Quantitative assessment of umbilical venous blood velocity with Doppler ultrasound (US) must cope with the coiled structure of the vein inside the cord. Both an experimental and a theoretical approach showed remarkable variations in the insonation angle when the probe was moved along the vein, provided the inclination between the Doppler probe and the cord was kept constant. Inaccurate signal processing, stochastic variability and flow disturbances could, however, mask the influence of the geometry. The above hypotheses were assessed by investigating five cords in vitro a few hours after delivery from normal pregnancies at term. The Doppler signal was sampled at different sites along each cord and the mean Doppler shift estimated by FFT spectral analysis, both directly and through the noise rejection D’Alessio’s algorithm, which proved effective in improving the Doppler shift estimate in condition of low signal-to–noise ratio (SNR).

A MORPHOLOGIC STUDY OF THE VASCULATURE OF MALIGNANT GLIOMAS USING THICK CELLOIDIN SECTIONS AND ALKALINE PHOSPHATASE STAIN

The combination of 100 microm thick celloidin sections and alkaline phosphatase (AP) enzyme histochemistry of the vascular endothelium offers a greatly enhanced, 3D morphologic perspective and reveals intricate details of the vasculature of brain. A study of tumor specimens obtained at craniotomy from 6 patients with glioblastomas, 1 with anaplastic oligodendroglioma and 1 with juvenile pilocytic astrocytoma was undertaken using this technique. Five of the 6 glioblastomas, the anaplastic oligodendroglioma and the low-grade astrocytoma specimen showed uniform staining of afferent tumor blood vessels. In the glioblastomas, newly formed vessels formed dense, festooned networks at the advancing edges of the tumor. Feeding arteries entered the tumor at the junction between the edge of the tumor and adjacent brain or meninges and proceeded to form striking, coiled vessels and smaller branches. The density of both small arteries and veins was greatly increased within the tumor although there was much variability. Disordered arborization, arteriole to venous and arteriole to arteriole shunts were observed, leading to a situation where arteries connected directly to veins. In necrotic areas, there were often no AP-stained vessels. In many places, arterioles and capillaries were lacking. Numerous AP-negative veins of various sizes drained the tumors. Glomeruloid proliferations were presumptively identified as focal stain smudges or clusters of capillaries arising from nearby vascular channels. Increased alkaline phosphatase staining and/or focal new vessels were seen outside necrotic areas. The pilocytic astrocytoma and the oligodendroglioma showed less dense vascularity and no formation of the focal festoons of vessels shown by the glioblastomas. This technique may be useful for the study of tumor angiogenesis and to evaluate vascularity in experimental and human brain tumors after various therapies.

The cochlear glomeruli in the modiolus of the guinea pig.

The cochlear glomeruli were studied in guinea pigs using scanning electron microscopy of vascular corrosion casts and transmission electron microscopy of tissue sections. Two types of coiled vessels forming the cochlear glomeruli were found in the bony wall of the modiolus. First, upper glomeruli were seen situated in the bony wall next to the scala vestibuli; second, lower glomeruli were located in the osseous spiral lamina just above the spiral ganglion. Upper glomeruli gave rise to radiating arterioles which supplied capillaries of the stria the spiral lamina and limbus. Unlike the main supplying arteries, smooth muscle cells were not present in the walls of the arterioles forming the glomeruli and a peculiar layer of lamellar pericytes was found. The arterioles were strikingly longer than their parent vessels and no autonomic nerves were found in close spatial relationship. Hence, these findings indicate that the cochlear glomeruli serve as efficient devices for reducing cochlear blood pressure.

Development of Inner Ear VesselsA Scanning Electron Microscopic Study

The development of the inner ear vessels of guinea pigs were studied by SEM. Employing 32- to 55-gestational-day-old guinea pig embryos, corrosion casts of inner ear blood vessels were prepared using Mercox resin and then observed by scanning electron microscopy. Between the 35th and 40th gestational days, the vascular structure of the vestibule was sufficiently developed, but the capillary network in the wall of the cochlea remained immature. Thus, in the guinea pig, the development of the vestibular structure precedes the development of the cochlear vessels. Moreover, at both sites, the density of the embryonic blood vessels was high, and the vessels were believed to transport a large blood flow. From about the 40th day of gestation, the coiled vessels and the capillary network in the lateral wall of the cochlea underwent rapid development, and the vascular structure in both the vestibule and cochlea was nearly complete by the time of birth.