Collagen Bundles Research Articles

Intramedullary sclerosing meningioma: operative video.

Sclerosing meningiomas (SMs) represent a rare histological variant of meningiomas, first described in 1989 as invasive bulking masses of whorling collagen bundles with a minimum percentage of meningothelia-resembling cells, and they are often misdiagnosed. The literature reports only 30 cases of SMs, with only two of them being intramedullary. The authors present the case of a patient with a cervical intramedullary SM who presented with gait disturbances, sensory deficits, weakness in four extremities, and hyperreflexia. The surgery was performed under neurophysiological monitoring and after administration of sodium fluorescein, which allowed us to discriminate the exact myelotomy point. Intramedullary SMs are very rare entities whose correct management may result in a good outcome.

New insights into lacrimal gland anatomy using 7T MRI and electron microscopy: Relevance for lacrimal gland targeted therapies and bioengineering

PurposeTo study the tissue architecture, isthmus (connection between two lobes) of the lacrimal gland using preclinical 7T MRI in combination with histology and electron microscopy. MethodsTen lacrimal glands from Caucasian body donors (mean age 78.7 years) were studied using 7T-MRI (N = 5; scanned at 75-μm intervals), histology, and electron microscopy (N = 5) and 3D cinematic rendering (CR) techniques. Results3D CR images showed uniform-sized lobules (widest lobule diameter, 1.68 ± 0.19 mm in orbital lobe, 1.68 ± 0.17 mm in palpebral lobe) in both lobes, separated by septae (size, 0.29 ± 0.09 mm). The internal framework of the gland resembled a honeycoomb pattern. In CR and histology, the isthmus contained glandular acini, large blood vessels, nerves, and no more than two ducts having a tortuous course towards the conjunctival surface. On assigning a color display to the rendered lacrimal gland, all glands showed a blood vessel originating from the main lacrimal artery just 5 mm beyond the hilum and making it course to the palpebral lobe via isthmus. The distance between the conjunctiva and the central substance of the orbital and palpebral lobe was 9.4 ± 0.2 mm and 2.8 ± 0.7 mm, respectively. Electron microscopy of the palpebral lobe revealed compact subepithelial layer in the overlying conjunctiva, followed by loosely scattered collagen bundles that contained the gland lobules. Conclusion3D-CR can be used to study the lacrimal gland microstructure, help fabricate a 3D scaffold for lacrimal gland bioprinting, and serve as guide for transconjunctival lacrimal gland targeted therapies i.e., 2.9 & 9 mm long needle to reach the orbital and palpebral lobe center, respectively in normal-size glands.

A case-control study addressing the population of epidermal and dermal inflammatory infiltrate including neural milieu in primary prurigo nodularis using S-100 and toluidine blue stain and its therapeutic implications.

The pathogenesis of prurigo nodularis (PN) is considered to be multifactorial, with numerous cells and cytokines confabulating to produce an aberrant immune response. A cross-sectional observational study was done in cases of untreated primary prurigo nodularis cases with histopathological assessment in 49 cases from lesional and nonlesional skin with assessment of epidermal and dermal changes, dermal infiltrate, S-100 andtoluidine blue staining to assess the expression of nerve and mast cells. The most common histological changes seen in lesional skin were hyperkeratosis (98%), irregular hyperplasia (69.4%), hypergranulosis (69.4%), subepidermal clefting (6%), vertical collagen bundles (51.0%), and dermal fibrosis (48.9%). Chronic inflammatory infiltrate was seen in all cases (100%) predominantly of lymphocytes (100%) followed by eosinophils (18.4%), plasma cells (8.2%), and neutrophils (2.0%). There was a marked increase in the expression of S-100 (6.92 ± 3.40 vs. 3.94 ± 2.15, P < 0.001) and toluidine blue (4.99 ± 4.47 vs. 1.22 ± 1.28, P < 0.001) in the lesional skin as compared to the nonlesional skin. We can infer that the epidermal and dermal pathology in PN is related to the infiltrate of lymphocytes, mast cells, and neural hyperplasia which perpetuate the pathogenesis by triggering the itch-inflammation cycle. Thus, apart from immunosuppressive agents that target lymphocytes and their cytokines, therapy targeted at mast cells and neural proliferation may be needed to treat prurigo nodularis.

Concordance of in vivo reflectance confocal microscopy and horizontal-sectioning histology in skin tumours.

In vivo reflectance confocal microscopy (RCM) enables the study of architectural and cytological aspects in horizontal sections, which closely correlate with histologic features. However, traditional histopathological vertical sections cannot totally reproduce the image of the in vivo RCM horizontal section. To evaluate the concordance between in vivo RCM and histopathologic transverse sections for melanocytic lesions, basal cell carcinoma and seborrheic keratoses. Prospectively collected benign melanocytic and non-melanocytic tumours diagnosed by dermoscopy were evaluated for common RCM features and compared to histopathology in horizontal sections with haematoxylin and eosin staining. A total of 44 skin tumours including 19 melanocytic lesions (nine compound, five junctional and five intradermal nevi), 12 basal cell carcinomas and 13 seborrheic keratoses were collected in the Department of Dermatology of Hospital Clinic of Barcelona. The RCM features that had statistically significant agreement with the histopathological horizontal sections were the preserved and visible honeycomb pattern, well defined DEJ, small bright particles, dermal nests, tumour islands and dark silhouettes, clefting, collagen bundles, thickened collagen bundles and cytologic atypia. Histopathology evaluation of horizontal sections of skin tumours can be correlated with main RCM findings. The results of this study have improved the understanding and interpretation of RCM features in relation to skin tumours, thus reinforcing the utility of RCM as a diagnostic tool.

Meniscal Fibrocartilage Repair Based on Developmental Characteristics: A Proof-of-Concept Study

Background: Unlike the adult meniscus, the fetal meniscus possesses robust healing capacity. The dense and stiff matrix of the adult meniscus provides a biophysical barrier for cell migration, which is not present in the fetal meniscus. Inspired by developmental characteristics, modifying the matrix of the adult meniscus into a fetal-like, loose and soft microenvironment holds opportunity to facilitate repair, especially in the avascular zone. Hypothesis: Modifying the dense and stiff matrix of the adult meniscus into a fetal-like, loose and soft microenvironment could enhance cell migration to the tear interface and subsequent robust healing capacity. Study Design: Controlled laboratory study. Methods: Fresh porcine menisci were treated with hyaluronidase or collagenase. The density and arrangement of collagen fibers were assessed. The degradation of proteoglycans and collagen was evaluated histologically. Cell migration within the meniscus or the infiltration of exogenous cells into the meniscus was examined. Dendritic silica nanoparticles with relatively large pores were used to encapsulate hyaluronidase for rapid release. Mesoporous silica nanoparticles with relatively small pores were used to encapsulate transforming growth factor–beta 3 (TGF-β3) for slow release. A total of 24 mature male rabbits were included. A longitudinal vertical tear (0.5 cm in length) was prepared in the avascular zone of the medial meniscus. The tear was repaired with suture, repaired with suture in addition to blank silica nanoparticles, or repaired with suture in addition to silica nanoparticles releasing hyaluronidase and TGF-β3. Animals were sacrificed at 12 months postoperatively. Meniscal repair was evaluated macroscopically and histologically. Results: The gaps between collagen bundles increased after hyaluronidase treatment, while collagenase treatment resulted in collagen disruption. Proteoglycans degraded after hyaluronidase treatment in a dose-dependent manner, but collagen integrity was maintained. Hyaluronidase treatment enhanced the migration and infiltration of cells within meniscal tissue. Last, the application of fibrin gel and the delivery system of silica nanoparticles encapsulating hyaluronidase and TGF-β3 enhanced meniscal repair responses in an orthotopic longitudinal vertical tear model. Conclusion: The gradient release of hyaluronidase and TGF-β3 removed biophysical barriers for cell migration, creating a fetal-like, loose and soft microenvironment, and enhanced the fibrochondrogenic phenotype of reparative cells, facilitating the synthesis of matrix and tissue integration. Clinical Relevance: Modifying the adult matrix into a fetal-like, loose and soft microenvironment via the local gradient release of hyaluronidase and TGF-β3 enhanced the healing capacity of the meniscus.

Neurofibroma of breast- A rare case report

Neurofibroma are benign tumour of peripheral nerve sheath that are mostly sporadic. Solitary neurofibromas of breast are uncommon. In this study, a case of 21-year-old female was referred with complaint of hyper pigmented lump in left breast since birth with recent increase in size for 5 months. Ultrasonography revealed a well-defined hypoechoic Space occupying lesion in subcutaneous plane at 11’o clock position of left breast along with a large ill-defined hypoechoic area with normal vascularity noted extending from 11’o clock to 2’o clock areas in left breast. Microscopically, the underlying stroma showed proliferating spindle cells with interspersed collagen bundles. Spindle cells show bland serpentine (wavy dark) nuclei and scant cytoplasm.

Experimental inoculation of the Botox perineurally of facial nerve and followed by histological assessment for its effect on the zygomatic bone of rabbits

Background: Botox, derived from the toxin produced by Clostridium botulinum, is an attenuated toxin employed as a treatment for cervical dystonia, overactive bladder, strabismus, cerebral palsy, and non-surgical cosmetic procedures. This study aimed to explore the impact of injecting Botox around the facial nerve on the left side of rabbits, specifically focusing on the histological changes in the zygomatic bone. Methods: Twenty-five adult rabbits of a local breed, weighing 1500-1800 gm and of both sexes, underwent a 15-day acclimation period prior to the experiment. The rabbits were randomly assigned to four groups (1st, 2nd, 3rd, and 4th). A singular intramuscular injection of Botox at a dose of 3.5 U/kg was administered to the left facial muscles. The rabbits in each group were then sacrificed at distinct time points after injection: day 10, day 15, day 30, and day 45. All rabbits survived until the end of the experiment, at which point they were euthanized with chloroform. Post-euthanasia, the rabbits' facial zygomatic bones were dissected and subjected to histological assessment. Results: The results indicated notable changes in the zygomatic bone, including prominent vacuoles within the bony matrix, cracks with cellular debris, limited osteocytes, and collagen bundles resembling woven bone. Additionally, in the day 30 group (T3), irregular bone borders and atrophied osteogenic cells were observed, while the day 45 group (T4) exhibited necrotic areas and bone fragments within the bone matrix. Conclusion: In conclusion, Botox, derived from Clostridium botulinum, serves various medical purposes. The study focused on injecting Botox around rabbits' facial nerves to assess its impact on zygomatic bones histologically. Following a controlled injection and specific time intervals, the examined bone samples exhibited distinct changes, providing insights into Botox's effects on bone morphology.

Isolated collagenoma in an HIV-positive patient on ART: a case report

BackgroundCollagenomas are rare connective tissue hamartomas composed of dermal collagen. Patients infected with human immunodeficiency virus (HIV) can present with HIV-related lipodystrophy or lipomas. There are no known associations between HIV and collagenomas.Case presentationHere we describe a case of an isolated collagenoma in an HIV patient on ART. The lesion was a seven by four-centimeter subcutaneous nodule with no epidermal changes located on the occipital scalp. This lesion was excised, and histopathology showed thick and randomly arranged collagen bundles, consistent with a collagenoma.ConclusionThis case represents an isolated collagenoma presenting in a patient with HIV. It is unclear whether HIV or ART contributed to the development of this collagenoma. Treatment of collagenomas include surgical excision and intralesional corticosteroids. In addition to lipoma or lipodystrophy, it is important to keep collagenoma in the differential diagnosis in a patient presenting with an isolated large indurated subcutaneous nodule.

Electron Microscopy (EM) Analysis of Collagen Fibers in the Peri-Implant Soft Tissues around Two Different Abutments.

The design of the implant prosthesis-abutment complex appears crucial for shaping healthy and stable peri-implant soft tissues. The aim of the present animal study was to compare two implants with different healing abutment geometries: a concave design (TEST) and a straight one (CTRL). Transmission electron microscopy (TEM) was used to quantify the three-dimensional topography and morphological properties of collagen at nanoscale resolution. 2 swine were included in the experiment and 6 implants per animal were randomly placed in the left or right hemimandible in either the physiologically mature bone present between the lower canine and first premolar or in the mandibular premolar area, within tooth extraction sites. Each CTRL implant was positioned across from its respective TEST implant on the other side of the jaw. After 12 weeks of healing, 8 specimens (4 CTRL and 4 TEST) were retrieved and prepared for histological and TEM analysis. The results showed a significantly higher percentage of area covered by collagen bundles and average bundle size in TEST implants, as well as a significant decrease in the number of longitudinally oriented bundles with respect to CTRL implants, which is potentially due to the larger size of TEST bundles. These data suggest that a concave transmucosal abutment design serves as a scaffold, favoring the deposition and growth of a well-organized peri-implant collagen structure over the implant platform in the early healing phase, also promoting the convergence of collagen fibers toward the abutment collar.

Fabrication, characterization and potential application of biodegradable polydopamine-modified scaffolds based on natural macromolecules

Sodium alginate (SA)-based implantable scaffolds with slow-release drugs have become increasingly important in the fields of biomedical and tissue engineering. However, high-molecular-weight SA is difficult to remove from the body due to the lack of SA-degrading enzymes. The very slow degradation properties of SA-based scaffolds limit their applications. Herein, we designed a series of biodegradable oxidized SA (OSA)-based scaffolds through amide bonds, imine bonds and hydrogen bridges between OSA and silk fibroin (SF). SF/OSA-0.4 with a blend ratio of 4/1 was chosen for further polydopamine (PDA) surface modification studies through the optimization of those parameters such as different OSA oxidation degrees, and blend ratios. PDA modified SF/OSA-0.4 (Dopa/SF/OSA-0.4) showed the excellent stability, better stretchable properties, a uniform interconnective porous structure, high thermal stability, a low hemolysis ratio and cytotoxicity. In vitro degradation experiments showed that the degradation rate of SF/OSA was significantly higher than that of SF/SA, but the degradation slowed again after PDA modification. Interestingly, the degradation of Dopa/SF/OSA-0.4 in vivo was significantly faster than that in vitro. Dopa/SF/OSA-0.4 was also more conducive to new tissue growth and collagen bundle formation. Moreover, Dopa/SF/OSA-0.4 improved the absorbability of RhB (model drug) and reduced the sudden release of RhB during the sustained release.

AUTOMATED DETECTION OF COLLAGEN BUNDLES ON SECOND HARMONIC GENERATION IMAGES

Collagen is one of the most abundant proteins&#x0D; in the body. It is essential for the structure, functionality, and&#x0D; strength of the connective tissue such as skin, bone, tendon,&#x0D; and cornea. It is known that a change in the arrangement&#x0D; or morphology of these fibrillar structures relates to multiple&#x0D; dysfunctions including corneal diseases and various cancer types.&#x0D; Due to their critical roles in wide-range abnormalities, there&#x0D; is an increasing interest in the pattern analysis of collagen&#x0D; arrangements. In recent years, Second Harmonic Generation&#x0D; (SHG) microscopy is proven to be an efficient imaging modality&#x0D; for visualizing unstained collagen fibrils. There are plenty of&#x0D; studies in the literature on the analysis of collagen distribution&#x0D; in SHG images. However, the majority of these methods are&#x0D; limited to detecting simple, statistical and non-local properties&#x0D; such as pixel intensity and orientation variance. There is a&#x0D; need for a method to detect the local structural properties of&#x0D; collagen bundles. This paper is to introduce an automated method&#x0D; to detect collagen bundles in 3-dimensional SHG microscopy&#x0D; images. The origin of the proposed method is based on multiscale&#x0D; directional representation systems. The proposed method detects&#x0D; the collagen bundles by measuring the dominant orientation&#x0D; of local regions and an orientation-based connected component&#x0D; analysis. Through more local analysis and the detection of&#x0D; collagen bundles separately, the proposed method would lead to&#x0D; the extraction of more detailed structural information on collagen&#x0D; bundle distribution.

Relapsing subcutaneous nodules of the penis in a pediatric patient.

A 14-year-old boy presented with a history of non-tender, subcutaneous coalescing nodules located on the ventral-lateral aspects of the penis shaft for one year. Laboratory investigations for blood count and autoimmunity were within normal limits. Complete excision was performed, and on histology, the dermis showed necrobiotic material composed of altered collagen bundles, surrounded by a palisade of histiocytes and scattered lymphocytes, thus allowing a diagnosis of subcutaneous granuloma annulare. Only 18 published cases reported penile granuloma annulare. Medical management was advocated in 7/18 cases, either as a first-line or adjuvant therapy where surgery was not radical. Three patients received high-potency local steroids: two cases underwent adjuvant sessions of intralesional triamcinolone, and one patient received pentoxifylline orally. Surgery should be considered a second-line option since 5/8 of treated cases eventually recurred. The pentoxifylline-treated case witnessed a relapse after drug discontinuation, while topical steroids lead to complete recovery without relapses.

Full-thickness skin rejuvenation by a novel dual-length microneedle radiofrequency device: A proof-of-concept study using human skin.

A novel dual-length microneedle radiofrequency (DLMR) device has been developed to achieve full-thickness skin rejuvenation by stimulating the papillary and reticular dermis simultaneously. This device's dual-level targeting concept need to be validated on human skin, although its clinical efficacy has been demonstrated in a previous study. This study evaluated the dual-depth targeting capability and the ability to induce rejuvenation in each layer of vertical skin anatomy, that is, the epidermis, papillary dermis, and reticular dermis, using full-thickness human facial skin samples. Human facial skin samples were obtained from 13 Asian patients who had facelift surgery. To validate the dual-depth targeting concept, DMLR-treated skin samples were analyzed using a digital microscope, thermal imaging, and hematoloxylin and eosin (H&E) staining immediately after DLMR application. On samples stained with H&E, Masson's tricrome, and Verhoeff-Van Gieson, histological observation and morphometric analysis were performed. Total collagen assay (TCA) and quantitative real-time polymerase chain reaction (qPCR) were used to assess changes in total collagen content and mRNA expression levels of collagen types I/III and vimentin, respectively. The DLMR device successfully induced thermal stimulation in the papillary and reticular dermis. The thickness, stacks, and dermal-epidermal junction convolution of the epidermis treated with DLMR were significantly increased. Collagen bundles in the dermis treated with DLMR exhibited a notable increase in thickness, density, and horizontal alignment. Dermal collagen levels were significantly higher in the morphometric and TCA data, as well as in the qPCR data for dermal matrix proteins. Our DLMR device independently and precisely targeted the papillary and reticular dermis, and it appears to be an effective modality for implementing full-thickness rejuvenation.

Co-Culture of Mouse Blastocysts on A Human Recellularized Endometrial Scaffold: An In Vitro Model for Future Implantation Studies.

This study evaluates the interaction of mouse blastocysts as a surrogate embryo on a recellularized endometrial scaffold by seeding human endometrial mesenchymal cells (hEMCs). In this experimental study, prepared decellularized human endometrial tissues were characterized by morphological staining, DNA content analysis, and scanning electron microscopic (SEM) analysis. The scaffolds were subsequently recellularized by hEMCs. After seven days of cultivation, the mouse blastocysts were co-cultured on the recellularized scaffolds for 48 hours. Embryo attachment and implantation within these scaffolds were evaluated at the morphological, ultrastructural, molecular, and hormonal levels. There was no morphological evidence of cells and nuclei in the decellularized scaffold. DNA content significantly decreased by 89.92% compared to the control group (P<0.05). Both decellularized and native tissues had similar patterns of collagen bundles and elastin fibers, and glycosaminoglycan (GAGs) distribution in the stroma. After recellularization, the hEMCs attached to the scaffold surface and penetrated different parts of these scaffolds. In the co-cultured group, the embryo attached to the surface of the scaffold after 24 hours and penetrated the recellularized endometrial tissue after 48 hours. We observed multi-layered organoid-like structures formed by hEMC proliferation. The relative expressions of epithelial-related genes, ZO-1 and COL4A1, and SSP1, MMP2, and PRL, as decidualizationrelated genes, were significantly higher in the recellularized group on day 9 in the presence of the embryo compared to the other groups (P<0.05). Beta human chorionic gonadotropin (β-hCG) and prolactin were statistically increased in the recellularized group on day 9 group (P<0.05). hEMCs and mouse embryo co-cultured on a decellularized endometrial scaffold provides an alternative model to study embryo implantation and the earlier stage of embryo development.

Unraveling the biomechanical properties of collagenous tissues pathologies using synchrotron-based phase-contrast microtomography with deep learning

Mechanical stimuli are regulators not only in cells but also of the extracellular matrix activity, with special reference to collagen bundles composition, amount and distribution. Synchrotron-based phase-contrast computed tomography was widely demonstrated to resolve collagen bundles in 3D in several body districts and in both pre-clinical and clinical contexts. In this perspective study we hypothesized, supporting the rationale with synchrotron imaging experimental examples, that deep learning semantic image segmentation can better identify and classify collagen bundles compared to common thresholding segmentation techniques. Indeed, with the support of neural networks and deep learning, it is possible to quantify structures in synchrotron phase-contrast images that were not distinguishable before. In particular, collagen bundles can be identified by their orientation and not only by their physical densities, as was made possible using conventional thresholding segmentation techniques. Indeed, localised changes in fiber orientation, curvature and strain may involve changes in regional strain transfer and mechanical function (e.g., tissue compliance), with consequent pathophysiological implications, including developmental of defects, fibrosis, inflammatory diseases, tumor growth and metastasis. Thus, the comprehension of these kinetics processes can foster and accelerate the discovery of therapeutic approaches for the maintaining or re-establishment of correct tissue tensions, as a key to successful and regulated tissues remodeling/repairing and wound healing.

Detection of Mast Cells in Human Superficial Fascia.

The recent findings showed that the superficial fascia is a fibrous layer in the middle of hypodermis, richly innervated and vascularized, and more complex than so far demonstrated. This study showed the presence of mast cells in the superficial fascia of the human abdomen wall of three adult volunteer patients (mean age 42 ± 4 years; 2 females, 1 male), by Toluidine Blue and Safranin-O stains and Transmission Electron Microscopy. Mast cells are distributed among the collagen bundles and the elastic fibers, near the vessels and close to the nerves supplying the tissue, with an average density of 20.4 ± 9.4/mm2. The demonstration of the presence of mast cells in the human superficial fascia highlights the possible involvement of the tissue in the inflammatory process, and in tissue healing and regeneration processes. A clear knowledge of this anatomical structure of the hypodermis is fundamental for a good comprehension of some fascial dysfunctions and for a better-targeted clinical practice.

The Combinatory Effects of Zinc Oxide Nanoparticles (ZnO NPs) and Thiamine on Skin of Alloxan-Induced Diabetic Mice; a Stereological and Biochemical Study

This study aimed to investigate the treatment effects of ZnO NPs plus thiamine on histo-stereological and biochemical parameters in diabetic mouse skin. In total 54 BALB/C mice were used and divided into nine groups. Twenty-four mice were coordinately assigned as control groups (I), thiamine (II), and zinc oxide nanoparticles (III and IV; 1.0 and 5.0 mg/kg). Diabetes was induced in the remaining rats with a dose of 180 mg/kg of alloxan; diabetes group (group V). Other diabetic mice were treated with ZnO NPs (0.1 and 0.5 mg/kg) alone (groups VI and VII, respectively) and along with thiamine (groups VIII and IX, respectively). An increase in weight was observed in the diabetic group compared to the control group. Diabetic skin showed decreasing in volume density of collagen bundles and decreasing in the epidermis and dermis thickness, as well as an increase in the hypodermis's thickness. Administration of ZnO NPs (0.1 and 0.5 mg/kg) alone and along with thiamine in the diabetic animals resulted in anti-hyperglycemic activity, reducing GGT, BUN, Cr, MDA, and NO levels in treated diabetic mice. In conclusion, the concomitant use of ZnO NPs along with thiamine presents the potential as a combination therapy for the treatment of alloxan-induced diabetic mice skin changes.

Physical training promotes remodeling of the skeletal muscle extracellular matrix: An ultrastructural study in a murine model of Down syndrome.

Down syndrome (DS) is a genetically based disease caused by triplication of chromosome 21. DS is characterized by multi-systemic premature aging associated with deficit in motor coordination, balance, and postural control. Using a morphological, morphometrical, and immunocytochemical ultrastructural approach, this study investigated in vastus lateralis muscle of Ts65Dn mouse, a murine model of DS, the effect of an adapted physical training on the extracellular matrix (ECM) characteristics and whether the forecasted exercise-induced ECM remodeling impacts on sarcomere organization. Morphometry demonstrated thicker basement membrane and larger collagen bundles with larger interfibrillar spacing as well as irregularly arrayed myofibrils and lower telethonin density on Z-lines in trisomic versus euploid sedentary mice. In agreement with the multi-systemic premature aging described in DS, these ECM alterations were similar to those previously observed in skeletal muscle of aged mice. Adapted physical training induced remodeling of ECM in both trisomic and euploid mice, that is, enlargement of the collagen bundles associated with hypertrophy of collagen fibrils and reduction of the interfibrillar spacing. A re-alignment of the myofibrils and a higher telethonin density on Z-line was found in trisomic mice. Altogether, our findings suggest that physical training is an effective tool in limiting/counteracting the trisomy-associated musculoskeletal structural anomalies. The current findings constitute a solid experimental background for further study investigating the possible positive effect of physical training on skeletal muscle performance. RESEARCH HIGHLIGHTS: Vastus lateralis muscle of trisomic mice shows aging-like alterations of extracellular matrix. Training promotes extracellular matrix remodeling. Training may be an effective tool to counteract trisomy-associated alterations of skeletal muscle.

P08 Successful treatment of paediatric morphoea with tofacitinib

Abstract Morphoea is a chronic autoimmune fibrosing condition causing inflammation, skin sclerosis and underlying soft tissue. The Janus kinase (JAK)-STAT pathway is considered to be the downstream mediator in the process of promoting fibrosis by transforming growth factor-β, interleukin-6 and other factors and plays a signal transduction role in the process of fibrosis. JAK inhibitors have been shown in preclinical studies to inhibit the fibrotic pathway in systemic sclerosis (Celada LJ, Kropski JA, Herazo-Maya JD et al. PD-1 up-regulation on CD4(+) T cells promotes pulmonary fibrosis through STAT3-mediated IL-17A and TGF-beta1 production. Sci Transl Med 2018; 10). Here, we report the successful use of tofacitinib in two paediatric patients. Case 1 was a 6-year-old girl with a 4-year history of morphoea; case 2 was a 13-year-old boy, also with a 4-year history of morphoea. In case 1, we initiated tofacitinib therapy 2.5 mg twice daily, reduced the dose after 2 months and stopped using it after 8 months. For case 2, the dose was 5 mg twice daily for 5 months, considering the patient’s height and weight. We have seen a significant improvement in the appearance and pathology of the lesions. The Localized Scleroderma Cutaneous Assessment Tool (LoSCAT) was used to assess the disease activity and damage, and the post-treatment scores for both cases were significantly lower than before treatment. Skin biopsy in both cases after tofacitinib therapy revealed that collagen bundles were decreased in size and number, with decreased lymphocytic infiltration in the peripheral tissue. Immunofluorescence staining for case 1 showed that activated α-smooth muscle actin and myofibroblasts were significantly decreased after treatment of tofacitinib, mostly in the dermal papillary layer. The two patients remain under follow-up; neither of them has so far relapsed. To our knowledge, these are the first two paediatric cases of morphoea treated with tofacitinib to be reported in the literature. Disease progression was found to have been inhibited clinically and pathologically. The traditional treatment of morphoea with methotrexate, cyclophosphamide or mycophenolate mofetil is not invariably effective in our experience, especially in antifibrosis (Zhao M, Wu J, Wu H et al. Clinical treatment options in scleroderma: recommendations and comprehensive review. Clin Rev Allergy Immunol 2022; 62:273–91). Our results provide the rationale for large prospective cohort studies of tofacitinib in morphoea and other fibrotic disorders.

Influence of abutment macro- and micro-geometry on morphologic and morphometric features of peri-implant connective tissue.

The aim of the present human observational study is to provide morphologic and morphometric analysis of peri-implant connective tissue next to abutments with divergent or convergent macro-geometry and different surface micro-characteristics. Thirty patients were rehabilitated with single implants in the posterior area and one out of three different healing abutments with a one-stage technique: machined divergent abutment (DIV-MAC), machined convergent abutment (CONV-MAC) or convergent abutment with ultrathin threaded surface (CONV-UTM). At 3 months postimplant insertion, peri-implant soft tissue was harvested; the following outcomes were investigated: histomorphometry (vertical width of connective and epithelial components) as detected by histology and polarized light; and connective tissue vertical width and 3D organization as detected by synchrotron-based high-resolution phase-contrast-based tomography (PhC-μCT). Significant differences in connective tissue vertical dimension (aJE-AM) were found between DIV-MAC and both CONV-MAC and CONV-UTM, both by histology and PhC-μCT, with significantly higher values for the last two groups. Moreover, 2D histological analysis did not find significant differences in the junctional epithelium vertical dimension (PM-aJE). Importantly, PhC-μCT analysis revealed, at 3D level, significant greater amount and density of collagen bundles for CONV-UTM compared with the other two groups. Convergent abutment profiles, regardless of their surface micro-geometry, seem to favor axial development of peri-implant connective tissue. Moreover, ultrathin threaded surfaces seem associated with denser and greater connective tissue organization, which might improve peri-implant soft tissue seal.