Pigmented reticular structures in basal cell carcinoma and collision tumours.

BACKGROUND: The dermatoscopic diagnosis of basal cell carcinoma (BCC) is based on well-known specific criteria. Despite the fact that a pigment network is considered a negative feature for the diagnosis of BCC, its detection in a BCC context has been reported in 2.8% of cases. OBJECTIVES: To determine whether pigment networks or network-like structures might represent a pitfall for the correct diagnosis of BCC. METHODS: Dermatoscopic images of 412 histopathologically proven BCCs were analysed retrospectively. RESULTS: Pigment network or network-like structures were detected in 14 of 412 (3.4%) BCCs. Nine of 14 BCCs presented a typical pigment network, due to the association of a BCC lesion with a naevus, solar lentigo or actinic keratosis; two BCCs located on the face showed a pseudonetwork, and three of 14 lesions displayed a network-like structure characterized by light-brown irregularly meshed short linear structures, histopathologically related to a hyperpigmentation of the basal layer of the epidermis. CONCLUSIONS: The presence of a pigment network in the context of a BCC is uncommon, and it usually reflects the association of BCC with a solar lentigo, naevus or a specific location of the lesion on photodamaged skin.

X-ray scanning microscopies of microcalcifications in abdominal aortic and popliteal artery aneurysms.

Abdominal aortic and popliteal artery aneurysms are vascular diseases which show massive degeneration, weakening of the vascular wall and loss of the vascular tissue functionality. They are driven by inflammatory, hemodynamical factors and biological alterations that may lead, in the case of an abdominal aortic aneurysm, to sudden and dangerous ruptures of the arteries. Here, human aortic and popliteal aneurysm tissues were obtained during surgical repair, and studied by synchrotron radiation X-ray scanning microdiffraction and small-angle scattering, to investigate the microcalcifications present in the tissues. Data collected during the experiments were transformed into quantitative microscopy images through the combination of statistical approaches and crystallographic methods. As a result of this multi-step analysis, microcalcifications, which are markers of the pathology, were classified in terms of chemical and structural content. This analysis helped to identify the presence of nanocrystalline hy-droxy-apatite and microcrystalline cholesterol, embedded in myofilament, and elastin-containing tissue with low collagen content in predominantly nanocrystalline areas. The generality of the approach allows it to be transferred to other types of tissue and other pathologies affected by microcalcifications, such as thyroid carcinoma, breast cancer, testicular microli-thia-sis or glioblastoma.

Effects of processing on structural, mechanical and biological properties of collagen-based substrates for regenerative medicine.

The aim of this work was to investigate the structural features of type I collagen isoforms and collagen-based films at atomic and molecular scales, in order to evaluate whether and to what extent different protocols of slurry synthesis may change the protein structure and the final properties of the developed scaffolds. Wide Angle X-ray Scattering data on raw materials demonstrated the preferential orientation of collagen molecules in equine tendon-derived collagens, while randomly oriented molecules were found in bovine skin collagens, together with a lower crystalline degree, analyzed by the assessment of FWHM (Full Width at Half Maximum), and a certain degree of salt contamination. WAXS and FT-IR (Fourier Transform Infrared) analyses on bovine collagen-based films, showed that mechanical homogenization of slurry in acidic solution was the treatment ensuring a high content of super-organization of collagen into triple helices and a high crystalline domain into the material. In vitro tests on rat Schwannoma cells showed that Schwann cell differentiation into myelinating cells was dependent on the specific collagen film being used, and was found to be stimulated in case of homogenization-treated samples. Finally DHT/EDC crosslinking treatment was shown to affect mechanical stiffness of films depending on collagen source and processing conditions.

Interfibrillar packing of bovine cornea by table-top and synchrotron scanning SAXS microscopy.

Bovine cornea was studied with scanning small-angle X-ray scattering (SAXS) microscopy, by using both synchrotron radiation and a microfocus laboratory source. A combination of statistical (adaptive binning and canonical correlation analysis) and crystallographic (pair distribution function analysis) approaches allowed inspection of the collagen lateral packing of the supramolecular structure. Results reveal (i) a decrease of the interfibrillar distance and of the shell thickness around the fibrils from the periphery to the center of the cornea, (ii) a uniform fibril diameter across the explored area, and (iii) a distorted quasi-hexagonal arrangement of the collagen fibrils. The results are in agreement with existing literature. The overlap between laboratory and synchrotron-radiation data opens new perspectives for further studies on collagen-based/engineered tissues by the SAXS microscopy technique at laboratory-scale facilities.

An optimized table-top small-angle X-ray scattering set-up for the nanoscale structural analysis of soft matter.

The paper shows how a table top superbright microfocus laboratory X-ray source and an innovative restoring-data algorithm, used in combination, allow to analyze the super molecular structure of soft matter by means of Small Angle X-ray Scattering ex-situ experiments. The proposed theoretical approach is aimed to restore diffraction features from SAXS profiles collected from low scattering biomaterials or soft tissues, and therefore to deal with extremely noisy diffraction SAXS profiles/maps. As biological test cases we inspected: i) residues of exosomes' drops from healthy epithelial colon cell line and colorectal cancer cells; ii) collagen/human elastin artificial scaffolds developed for vascular tissue engineering applications; iii) apoferritin protein in solution. Our results show how this combination can provide morphological/structural nanoscale information to characterize new artificial biomaterials and/or to get insight into the transition between healthy and pathological tissues during the progression of a disease, or to morphologically characterize nanoscale proteins, based on SAXS data collected in a room-sized laboratory.

Correlative light and scanning X-ray scattering microscopy of healthy and pathologic human bone sections.

Scanning small and wide angle X-ray scattering (scanning SWAXS) experiments were performed on healthy and pathologic human bone sections. Via crystallographic tools the data were transformed into quantitative images and as such compared with circularly polarized light (CPL) microscopy images. SWAXS and CPL images allowed extracting information of the mineral nanocrystalline phase embedded, with and without preferred orientation, in the collagen fibrils, mapping local changes at sub-osteon resolution. This favorable combination has been applied for the first time to biopsies of dwarfism syndrome and Paget's disease to shed light onto the cortical structure of natural bone in healthy and pathologic sections.

Peripheral blood T lymphocyte subpopulations in newborns.

Monocyte-depleted lymphocyte suspensions from the peripheral blood of 36 healthy newborns and 23 adults were compared as to percent of cells forming rosettes with sheep erythrocytes (T lymphocytes) and proliferative responses after in vitro culture with various doses of Phytohemagglutinin, Concanavalin A and Pokeweed mitogen. No significant difference was found between the proportions of T lymphocytes of newborns and adults. Mitogen responsiveness of the newborn lymphocytes showed dramatic between-subject variability completely unrelated to the proportion of T lymphocytes. It is suggested that during neonatal life there is massive variable recirculation of T lymphocytes subsets (and/or stages of maturation) characterized by differential degrees of responsiveness to the mitogens tested.