A. Manelli

Microvascularization of the human digit as studied by corrosion casting

The aim of this study was to describe microcirculation in the human digit, focusing on the vascular patterns of its cutaneous and subcutaneous areas. We injected a functional supranumerary human thumb (Wassel type IV) with a low‐viscosity acrylic resin through its digital artery. The tissues around the vessels were then digested in hot alkali and the resulting casts treated for scanning electron microscopy. We concentrated on six different areas: the palmar and dorsal side of the skin, the eponychium, the perionychium, the nail bed and the nail root. On the palmar side, many vascular villi were evident: these capillaries followed the arrangement of the fingerprint lines, whereas on the dorsal side they were scattered irregularly inside the dermal papillae. In the hypodermal layer of the palmar area, vascular supports of sweat glands and many arteriovenous anastomoses were visible, along with glomerular‐shaped vessels involved in thermic regulation and tactile function. In the eponychium and perionychium, the vascular villi followed the direction of nail growth. In the face of the eponychium in contact with the nail, a wide‐mesh net of capillaries was evident. In the nail bed, the vessels were arranged in many longitudinal trabeculae parallel to the major axis of the digit. In the root of the nail, we found many columnar vessels characterized by multiple angiogenic buttons on their surface.

Whiplash injury and oculomotor dysfunctions: clinical-posturographic correlations.

Oculomotor dysfunctions are hidden causes of invalidity following whiplash injury. Many patients with whiplash injury grade II present oculomotor dysfunctions related to input disturbances of cervical or vestibular afferents. We used static posturography to investigate 40 consecutive patients with whiplash injury grade II and oculomotor dysfunctions. We demonstrated a relation between length and surface of body sway: the surface value (A) was higher than the length value (L) and this led to an open graph of body sway in the statokinesigram. Oculomotor rehabilitation can resolve the impairment of vestibular function but if therapy is delayed or the patient has been wearing an orthopaedic neck collar, more therapeutic sessions are required. In conclusion, without rehabilitation of the oculomotor muscles other therapies are not sufficient to recover the impairment caused by whiplash injury.

Early-stage microvascular alterations of a new model of controlled cortical traumatic brain injury: 3D morphological analysis using scanning electron microscopy and corrosion casting

OBJECT This study was performed to study the microvascular changes that occur during the first 12 hours after traumatic brain injury (TBI) using the corrosion casting technique. METHODS The authors performed a qualitative and quantitative morphological study of the changes in cerebral vessels at acute (3 hours) and subacute (12 hours) stages after experimental TBI. They used a model of controlled cortical impact (CCI) injury induced by a recently developed electromagnetic device (impactor), focusing their observations mainly on the microvascular alterations responsible for the formation and maintenance of tissue edema and consequent brain swelling during the first hours after TBI. They used corrosion casting, scanning electron microscopy (SEM), light microscopy, and transmission electron microscopy (TEM) to obtain a morphological qualitative map with both 2D and 3D details. RESULTS Scanning electron microscopy analysis of vascular casts documented in 3 dimensions the typical injuries occurring after a TBI: subdural, subarachnoid, and intraparenchymal hemorrhages, along with alterations of the morphological characteristics and architecture of both medium-sized and capillary vessels, including ectasia of pial vessels, sphincter constrictions at the origin of the perforating vessels, focal swelling of perforating vessels, widening of intercellular junctions, and some indirect evidence of structural impairment of endothelial cells. All of these vascular alterations were confirmed in 2D analyses using light microscopy and TEM. CONCLUSIONS The corrosion casting-SEM technique applied to a CCI experimental model proved to be a reliable method for studying the pathophysiology of the vascular alterations occurring at acute and subacute stages after CCI injury. It was also possible to obtain topographical localization of the vascular and cellular events that usually lead to hyperemia, edema, and brain swelling. Moreover, by applying informatic software to anatomical images it was possible to perform quantification and statistical analysis of the observed events.

Plexiform vascular structures in the human digital dermal layer: a SEM--corrosion casting morphological study.

This study aimed to describe the impressive diversity of vascular plexiform structures of the hypodermal layer of human skin. We chose the human body site with the highest concentration of dermal corpuscles, the human digit, and processed it with the corrosion casting technique and scanning electron microscopy analysis (SEM). This approach proved to be the best tool to study these microvascular architectures, free from any interference by surrounding tissues. We took high-definition pictures of the vascular network of sweat glands, thermoreceptorial and tactile corpuscles, the vessels constituting the glomic bodies and those feeding the hair follicles. We observed that the three-dimensional disposition of these vessels strictly depends on the shape of the corpuscles supplied. We could see the tubular vascularization of the excretory duct of sweat glands and the ovoid one feeding their bodies, sometimes made up of two lobes. In some cases, knowledge of these morphological data regarding the normal disposition in space and intrinsic vascularization structure of the dermal corpuscles can help to explain many of the physiopathological changes occurring during chronic microangiopathic diseases.

The Cutaneous Microvascular Architecture of Human Diabetic Toe Studied by Corrosion Casting and Scanning Electron Microscopy Analysis

In this morphological study, we report on the three‐dimensional microvascular architecture constituting the toes of a patient affected by diabetic microangiopathy. We applied corrosion casting (CC) technique to the toes of a patient affected by Type 2 diabetes, who underwent surgery for explantation of inferior left limb due to necrotic processes of soft tissues. The toes of a foot traumatically explanted in a motorcycle accident were kept as controls. According to technical protocols, toes were injected with a low‐viscosity acrylic resin (Mercox) through the major digital artery, tissues were corroded in KOH solution (8%), and resulting casts processed for SEM observations. Already at low magnification, in diabetic toes, we found an impairment of the linear track‐like disposition of the vessels of plantar side, with signs of vascular disruption and obliterations, stopped resin, and leakages. Capillaries under the nail and a lot of vascular villi in eponychium and nail borders were damaged, and vascular regression phenomena acting on them were clearly visible. Resin leakages and impairment of normal vascular architecture were also observed in the root of the nail. This preliminary report represents only the first step for further investigations regarding morphological three‐dimensional appearance of diabetic microangiopathy. CC and scanning electron microscopy technique well documented these morphological modifications, highlighting on both structural and ultrastructural features of diabetic toes microvessels. In conclusion, our qualitative data try to better focus on the pathophysiological mechanisms involved in diabetic dermopathy and microangiopathy, proposing CC as useful method to investigate on them. Anat Rec 293:1639–1645, 2010.

Short-term evaluation of collagen meniscus implants by MRI and morphological analysis

Abstract Meniscectomy can lead to degenerative joint changes in the knee. Collagen meniscus implantation is a tissue engineering technique designed to stimulate regeneration of meniscal tissue in case of irreparable tears or previous meniscectomy. The implant is composed of type I collagen derived from bovine Achilles tendon and enriched with glycosaminoglycans. Previous clinical trials demonstrated satisfactory medium-term results in patients who received a collagen meniscus implant (CMI). In this study, CMI structure was analysed by light microscopy and scanning electronic microscopy (SEM). The same morphological studies were performed on two implant biopsies, obtained from two patients who underwent a second arthroscopic look six months after implantation. The evolution of the implant was also investigated by magnetic resonance imaging, 6 and 12 months postoperatively. CMI presented a multilamellar structure, with inner lacunae allowing tissue ingrowth. The lamellae were made of collagen fibrils, randomly oriented and preserving the typical 64-nm period. At second arthroscopic look, the implant appeared in continuity to the native residual meniscus and parameniscus, and showed good consistency and stability at probing. The biopsy specimens demonstrated invasion of the scaffold by connective tissue and blood vessels. The newly synthesised collagen fibrils were clearly distinguishable from the scaffold ones. No phagocytomacrophagic cells nor inflammatory reactions were observed inside the implant. MRI findings confirmed CMI biocompatibility and highlighted the evolution of the integration process with time. The data achieved in this study support the hypothesis that CMI stimulates regeneration of meniscal-like tissue, which could prevent the development of degenerative changes after meniscectomy.

Arterial and microvascular supply of cerebral hemispheres in the nude mouse revealed using corrosion casting and scanning electron microscopy

Morphological analyses of cerebral vascularization are not only important for the characterization of the anatomical and physiological relationships between vascular and nervous tissue, but also required to understand structural modifications that occur in many pathological conditions affecting the brain. The aim of this study was to generate a three‐dimensional vascular map of the cerebral hemispheres in the nude mouse brain, a widely used animal model for studying tumour biology. We used the corrosion casting (CC) technique to isolate blood vessels from 30 nude mouse brains. All casts were analysed using scanning electron microscopy (SEM), which generated quantitative data regarding vessel length and diameter as well as inter‐vascular and inter‐branching distances. We identified three different topographical regions: (i) the cortical region, characterized by a superficial wide sheet of vessels giving rise to terminal perforant vessels that penetrate the grey matter; (ii) the inner part of the grey matter, in which dense capillary nets form many flake‐like structures extending towards the grey–white matter boundary, where perforant vessels finally change direction and form a well‐defined vascular sheet; and (iii) the white matter layer, characterized by a more disorganized vascular architecture. In this study, we demonstrate the accuracy of the CC‐SEM method in revealing the 3D‐topographical organization of the vascular network of the normal nude mouse brain. These baseline data will serve as a reference for future anatomical investigations of pathological alterations, such as tumour infiltrations, using the nude mouse model.