Subcutaneous Blood Vessels Research Articles

Intravital microscopy at the single vessel level brings new insights of vascular modification mechanisms induced by electropermeabilization

Electroporation/electropermeabilization, i.e. the result of the application of electric pulses to tissues, is a physical method for delivery of exogenous molecules into cells. It is effective particularly for compounds with limited transmembrane transport. In vivo, electropermeabilization facilitates the delivery of chemotherapeutic drugs into tumor cells that is the basic mechanism of the antitumor effectiveness of electrochemotherapy. This therapy has also blood flow modifying effects in tissues. The aim of our present study was to understand and explain the effects of electropermeabilization on the dynamics (vasomotricity, permeability and recovery) of subcutaneous blood vessels towards different size of molecules. These features were measured in C57Bl/6 mice via a dorsal skin fold window chamber, using fluorescently labeled dextrans of different sizes, intravital fluorescence microscopy imaging and specific image analysis. Application of electric pulses on the skin in vivo resulted in a rapid increase in vascular permeability that gradually recovered to basal levels at different times post-treatment, depending on dextran size. Simultaneously, the immediate constriction of the blood vessels occurred that was more pronounced for arterioles compared to venules. This vasoconstriction of arterioles results in a transient “vascular lock”.The increased permeability of small vessels walls whatever the dextran size associated with delayed perfusion explains the improved delivery of the intravenous injected molecules (i.e. drugs, gene delivery) into the tissues induced by electropermeabilization in vivo.

Visualization of Blood Vessels Using Optical Coherence Tomography

New methods of optical coherence tomography (OCT) have been developed. OCT is a modern technique for noninvasive in vivo examination of upper layers of human skin and subcutaneous blood vessels using nonionizing radiation. The instruments described in this work use a low-power (0.2–0.4 mW) superluminescent diode. Several wavelengths can be applied simultaneously. Raster scanning and raster averaging in the interferometer sample arm increase the signal-to-noise ratio by 4–10 dB.

Optical Coherence-domain Imaging of Subcutaneous Human Blood Vessels in vivo

Experimental methods of Optical Coherence Tomography (OCT) are applied for two-dimensional mapping of subcutaneous human blood vessels. Structural images of in vivo human finger and human palm macro vessels (0.2-1.0 mm) before and after optical clearing using the modified low power rapid scanning optical delay line are presented. Images are scanned with 12 µm minimum spatial resolution. The described modifications enable to apply low power (0.4-0.5 mW), low noise broadband near infrared light source and to obtain structural images with detection of not only reflected but also multiply scattered coherence-gated photons. The achieved transcutaneous probing depth is about 1.6-1.8 mm.

Raster scanning and averaging for reducing the influence of speckles in optical coherence tomography

The application of small-angle raster scanning and averaging in the sample arm of the Michelson interferometer in optical coherence tomography (OCT) is described. Raster averaging is used to increase the signal-to-noise ratio and to reduce the speckle noise of the 2D OCT image in diagnostics of surface layers of human skin and subcutaneous blood vessels in vivo. The method allows using low-coherence source of low-power radiation and increasing the depth of human skin coherent probing up to 1.5 – 1.8 mm. The reduction of speckle noise in the obtained OCT image for the first time allowed visualisation of subcutaneous blood vessels at the entire depth of their localisation.

NoninvasiveIn-vivoMeasurements of Microvessels by Reflection-Type Micro Multipoint Laser Doppler Velocimeter

We have developed a micro multipoint laser Doppler velocimeter (µ-MLDV) that enables selective collection of Doppler interference photons. In previous report [H. Ishida et al.: Rev. Sci. Instrum. 82 (2011) 076104], developed the reflection-type µ-MLDV, and showed the results of demonstrations performed on transparent artificial flow channels. In this study, we attempted to perform in-vivo experiments using animals. It can measure absolute velocity and generate tomographs of blood vessels courses. The present system can perform noninvasive in-vivo measurements with a detection limit of about 0.5 mm/s and a spatial resolution in the x–y plane of 125 µm. It is thus able to image venulae. It was used to image venulae in a mouse ear and a subcutaneous blood vessel in a mouse abdomen at a depth of about 1.0 mm below the skin.

Noninvasive In-vivo Measurements of Microvessels by Reflection-Type Micro Multipoint Laser Doppler Velocimeter

We have developed a micro multipoint laser Doppler velocimeter (µ-MLDV) that enables selective collection of Doppler interference photons. In previous report [H. Ishida et al.: Rev. Sci. Instrum. 82 (2011) 076104], developed the reflection-type µ-MLDV, and showed the results of demonstrations performed on transparent artificial flow channels. In this study, we attempted to perform in-vivo experiments using animals. It can measure absolute velocity and generate tomographs of blood vessels courses. The present system can perform noninvasive in-vivo measurements with a detection limit of about 0.5 mm/s and a spatial resolution in the x–y plane of 125 µm. It is thus able to image venulae. It was used to image venulae in a mouse ear and a subcutaneous blood vessel in a mouse abdomen at a depth of about 1.0 mm below the skin.

Feature extraction from vein images using spatial information and chain codes

The pattern formed by subcutaneous blood vessels is unique attribute of each individual and can therefore be used as a biometric characteristic. Exploiting the specific near infrared light absorption properties of blood, the capture procedure for this biometric characteristic is convenient and allows contact-less sensors. However, image skeletons extracted from vein images are often unstable, because the raw vein images suffer from low contrast. We propose a new chain code based feature en- coding method, using spatial and orientation properties of vein patterns, which is capable of dealing with noisy and unstable image skeletons. Chain code comparison and a selection of preprocessing methods have been evaluated in a series of different experiments in single and multi-reference scenarios on two different vein image databases. The experiments showed that chain code comparison outperforms minutiae-based approaches and similarity based mix matching.

Intravascular Papillary Endothelial Hyperplasia (Masson tumor) of the Skull : Case Report and Literature Review

A 10-year-old female patient presented with a rapidly growing nodular mass lesion on her right frontal area. On skull radiography and computed tomography (CT) imaging, this mass had a well-demarcated punch-out lesion with a transdiploic, exophytic soft tissue mass nodule on the frontal scalp. Magnetic resonance (MR) imaging revealed the presence of a 1.5×1.2×1 cm sized calvarial lesion. This lesion was hypointense on T1 and heterogenous hyperintense on T2 weighted MR images, and exhibited heterogeneous enhancement of the soft tissue filling the punch-out lesion after intravenous administration of gadolinium. En block removal of the tumor with resection of the rim of the normal bone was performed. The pathological diagnosis was intravascular papillary endothelial hyperplasia (IPEH). After surgery, no recurrence was found for 8 months. IPEH is a rare and benign reactive lesion usually found in thrombosed subcutaneous blood vessels. Involvement of skull bone is rare. In this article, we present a case of IPEH involving the calvarium, in a 10-year-old woman.

Subcutaneous Fascial Bands—A Qualitative and Morphometric Analysis

BackgroundAlthough fascial bands within the subcutaneous (SQ) layer are commonly seen in ultrasound images, little is known about their functional role, much less their structural characteristics. This study's objective is to describe the morphological features of SQ fascial bands and to systematically evaluate the bands using image analyses tools and morphometric measures.MethodsIn 28 healthy volunteers, ultrasound images were obtained at three body locations: the lateral aspect of the upper arm, medial aspect of the thigh and posterior aspect of lower leg. Using image analytical techniques, the total SQ band area, fascial band number, fascial band thickness, and SQ zone (layer) thickness were determined. In addition, the SQ spatial coherence was calculated based on the eigenvalues associated with the largest and smallest eigenvectors of the images.ResultsFascial bands at these sites were contiguous with the dermis and the epimysium forming an interconnected network within the subcutaneous tissue. Subcutaneous blood vessels were also frequently encased by these fascial bands. The total SQ fascial band area was greater at the thigh and calf compared to the arm and was unrelated to SQ layer (zone) thickness. The thigh was associated with highest average number of fascial bands while calf was associated with the greatest average fascial band thickness. Across body regions, greater SQ zone thickness was associated with thinner fascial bands. SQ coherence was significantly associated with SQ zone thickness and body location (calf with statistically greater coherence compared to arm).ConclusionFascial bands are structural bridges that mechanically link the skin, subcutaneous layer, and deeper muscle layers. This cohesive network also encases subcutaneous vessels and may indirectly mediate blood flow. The quantity and morphological characteristics of the SQ fascial band may reflect the composite mechanical forces experienced by the body part.

The vascular aneurysms of Ehlers-Danlos syndrome type IV

A 32-year-old woman presented with severe left flank pain. On physical examination, the skin was so thin and pale that subcutaneous blood vessels were visible. An abdominal computed tomographic (CT) scan showed multiple renal infarctions in the left kidney and dissection with thrombus in aneurysmal dilated renal artery (diameter 8.1 mm) ( Panel A ). Stenting was performed using a 7 × 15 mm stent for the renal artery dissection ( Panel B ). The CT scan also showed multiple mesenteric artery aneurysms ( Panel …

Evaluation of the Effects of Urotensin II and Soluble Epoxide Hydrolase Inhibitor on Skin Microvessel Tone in Healthy Controls and Heart Failure Patients

Urotensin II (UII) is a potent vasoactive peptide that exerts differential effects on heart failure (HF) patients compared to health controls. However, the mechanism of action remains unclear. The role of soluble epoxide hydrolase (sEH) as a mediator of UII in the vasculature has not been explored. The aim of this study was to examine the effect of UII in the presence and absence of sEH inhibitor AUDA on skin microvessel tone in HF patients and healthy controls using iontophoresis and laser Doppler velocimetry. UII (10(-7) M) and AUDA (10(-10), 10(-7), and 10(-5) M) were administered to the forearm of participants by iontophoresis for 30 seconds. Laser Doppler velocimetry was performed for 5 minutes to measure flux through the subcutaneous blood vessels. Response (flux) was measured for 5 minutes per concentration with 25 continuous scans. UII increased flux in healthy controls by 39% (P < 0.05) and increased flux in HF patients by 6% (ns). AUDA (10(-10) and 10(-7) M) administration further decreased flux by 115% (P < 0.05) and 255% (P < 0.0001), respectively in healthy controls. In HF patients, AUDA (10(-10), 10(-7), and 10(-5) M) further increased flux by 77% (P < 0.05), 67% (P < 0.01), and 100% (P < 0.05), respectively. AUDA alone at 10(-7) M increased flux in both groups by 31% (healthy controls, P < 0.05) and 36% (HF, P < 0.01). Taken together, the presence of HF appeared to abrogate the vasodilator responsiveness of sEH inhibitor. These results suggest an important role for both UII and sEH in vascular regulation and that sEH may be involved in mediating UII effects. Furthermore, the study highlights the therapeutic potential of sEH inhibitors for the treatment of HF.

Further expansion of the phenotypic spectrum associated with mutations in ALDH18A1, encoding Δ1‐pyrroline‐5‐carboxylate synthase (P5CS)

We report on the third case of cutis laxa and progeroid features caused by a homozygous mutation in ALDH18A1 that encodes Δ¹-pyrroline-5-carboxylate-synthase (P5CS). This severely affected child, born to consanguineous parents of Pakistani origin, presented with lax, wrinkled and thin skin with dilated and tortuous subcutaneous blood vessels, corneal clouding, and hypotonia. The child had severe global developmental delay and feeding difficulties and died in infancy for an unknown reason. The proband was homozygous for a mutation in ALDH18A1, c.1923 + 1G > A which results in the production of two anomalous transcripts that are predicted to encode proteins lacking the catalytic site for the enzyme. The cellular phenotype is characterized by diminished production of collagen types I and III, altered elastin ultrastructure, and diminished cell proliferation of cultured dermal fibroblasts. This severe clinical and cellular phenotype overlaps with a broad group of neurocutaneous syndromes that include cutis laxa type II, wrinkly skin syndrome, de Barsy syndrome, and gerodermia osteodysplastica. The findings presented here emphasize the pleiotropic presentation of this group of conditions and suggest that multiple components of the extracellular matrix are perturbed in these disorders.

Frey Syndrome—An Underreported Complication to Closed Treatment of Mandibular Condyle Fracture? Case Report and Literature Review

The most common hypothesisis that regenerating parasympathetic fibers to sali-vary glands connect in error with the sweat glandsand subcutaneous blood vessels of the skin. Theonset has usually been 12 to 18 months after sur-gery. The most effective treatment has been subcu-taneous infiltration of botulinum toxin into the af-fected area.

Enhanced absorption of millimeter wave energy in murine subcutaneous blood vessels

The aim of the present study was to determine millimeter wave (MMW) absorption by blood vessels traversing the subcutaneous fat layer of murine skin. Most calculations were performed using the finite-difference time-domain (FDTD) technique. We used two types of models: (1) a rectangular block of multilayer tissue with blood vessels traversing the fat layer and (2) cylindrical models with circular and elliptical cross-sections simulating the real geometry of murine limbs. We found that the specific absorption rate (SAR) in blood vessels normally traversing the fat layer achieved its maximal value at the parallel orientation of the E-field to the vessel axis. At 42 GHz exposure, the maximal SAR in small blood vessels could be more than 30 times greater than that in the skin. The SAR increased with decreasing the blood vessel diameter and increasing the fat thickness. The SAR decreased with increasing the exposure frequency. When the cylindrical or elliptical models of murine limbs were exposed to plane MMW, the greatest absorption of MMW energy occurred in blood vessels located on the lateral areas of the limb model. At these areas the maximal SAR values were comparable with or were greater than the maximal SAR on the front surface of the skin. Enhanced absorption of MMW energy by blood vessels traversing the fat layer may play a primary role in initiating MMW effects on blood cells and vasodilatation of cutaneous blood vessels.

Follicular mucinosis: a case report

A case of follicular mucinosis is reported. A 60-year-old female was admitted to the hospital for facial nodules and infiltrated plaques over 1 year. Dermatological examination revealed skin-colored or pink nodules on the forehead and infiltrated plaques on the left chin covered with yellow crusts. The biopsy of a skin lesion demonstrated a mixed infiltrate of inflammatory cells which were predominated by lymphocytes, in dermis and around subcutaneous blood vessels and appendages. Reticular degeneration of follicular epithelial cells and formation of cysts were also observed. Alcian blue stain displayed massive mucin deposition in cyst cavity. After treatment with oral acitretin and prednisone and topical mometasone cream and isotretinoin gel for 2 months, the lesions disappeared. Key words: Mucinosis, follicular; Diagnosis; Therapy

Imaging of subcutaneous blood vessels and flow velocity profiles by optical coherence tomography

We have applied a compact low power rapid scanning Doppler Optical Coherence Tomography system to monitor multi-dimensional velocity profiles within the complex vessels and simultaneous real-time non-invasive imaging of skin tissues morphology in vivo, in the wavelength range of 1.3–1.5 nm. Optical clearing of skin tissues has been utilized to achieve depth of OCT images up to 1.7 mm. Current approach enables applying low-power (0.4–0.5 mW) and low-noise broadband near-infrared light sources and obtaining OCT images with down to 12 μm spatial resolution. Two-dimensional time-domain OCT images of complex flow velocity profiles in blood vessel phantom and in vivo subcutaneous human skin tissues are presented. The effect of optical clearing on in vivo images is demonstrated and discussed.

Donor-host involvement in immature rat testis xenografting into nude mouse hosts.

Immature testicular tissue of a wide variety of mammalian species continues growth and maturation when ectopically grafted under the dorsal skin of adult nude mouse recipients. Tissues from most donor species fully mature, exhibiting complete spermatogenesis within months. The connection to the recipient's vascular system is mandatory for graft development, and failure of vascularization leads to necrosis in the grafted tissue. In the present study, we analyze to what extent 1) the xenografted immature donor tissue and 2) the recipient's cells and tissues contribute to the functional recovery of a "testicular xenograft." We address whether recipient cells migrate into the testicular parenchyma and whether the circulatory connection between the donor testicular tissue and the recipient is established by ingrowing host or outgrowing donor blood vessels. Although this issue has been repeatedly discussed in previous xenografting studies, so far it has not been possible to unequivocally distinguish between donor and recipient tissues and thus to identify the mechanisms by which the circulatory connection is established. To facilitate the distinction of donor and recipient tissues, herein we used immature green fluorescent protein-positive rat testes as donor tissues and adult nude mice as graft recipients. At the time of graft recovery, donor tissues could be easily identified by the GFP expression in these tissues, allowing us to distinguish donor- and recipient-derived blood vessels. We conclude that the circulatory connection between graft and host is established by a combination of outgrowing small capillaries from the donor tissue and formation of larger vessels by the host, which connect the graft to subcutaneous blood vessels.

Surgical Management of Calciphylaxis Associated with Primary Hyperparathyroidism: A Case Report and Review of the Literature

Calciphylaxis, or calcific uremic arteriolopathy, commonly affects people with end-stage renal disease and carries with it a high rate of morbidity and mortality. Here, we present the unusual case of a 56-year-old woman, with extensive medical problems, who developed calciphylaxis in the presence of primary hyperparathyroidism. Our patient initially presented with bilateral, exquisitely tender thigh lesions. The diagnosis of calciphylaxis was rendered histologically by extensive calcification of the subcutaneous blood vessels. Subsequent parathyroidectomy identified the presence of a hyperactive mediastinal parathyroid adenoma, weighing 0.62 grams. Postoperatively, the patient had normalization of hypercalcemia and parathyroid hormone levels, with subsequent healing of her thigh wounds. Currently, there have been sixteen cases described in the English literature, with only nine being offered a potentially therapeutic parathyroidectomy. It is contingent upon the vigilant physician to diagnose and properly manage this difficult yet treatable condition.

A New Approach for Adipose Tissue Treatment and Body Contouring Using Radiofrequency-Assisted Liposuction

A new liposuction technology for adipocyte lipolysis and uniform three-dimensional tissue heating and contraction is presented. The technology is based on bipolar radiofrequency energy applied to the subcutaneous adipose tissue and subdermal skin surface. Preliminary clinical results, thermal monitoring, and histologic biopsies of the treated tissue demonstrate rapid preaspiration liquefaction of adipose tissue, coagulation of subcutaneous blood vessels, and uniform sustained heating of tissue.

Real-time in vivo photoacoustic and ultrasound imaging

A real-time photoacoustic imaging system is designed and built. This system is based on a commercially available ultrasound imaging system. It can achieve a frame rate of 8 frames/sec. Vasculature in the hand of a human volunteer is imaged, and the resulting photoacoustic image is combined with the ultrasound image. The real-time photo acoustic imaging system with a hybrid ultrasound probe is demonstrated by imaging the branching of subcutaneous blood vessels in the hand.