Features Of Connective Tissue Research Articles

Expanding the clinical spectrum of biglycan-related Meester-Loeys syndrome

Pathogenic loss-of-function variants in BGN, an X-linked gene encoding biglycan, are associated with Meester-Loeys syndrome (MRLS), a thoracic aortic aneurysm/dissection syndrome. Since the initial publication of five probands in 2017, we have considerably expanded our MRLS cohort to a total of 18 probands (16 males and 2 females). Segregation analyses identified 36 additional BGN variant-harboring family members (9 males and 27 females). The identified BGN variants were shown to lead to loss-of-function by cDNA and Western Blot analyses of skin fibroblasts or were strongly predicted to lead to loss-of-function based on the nature of the variant. No (likely) pathogenic missense variants without additional (predicted) splice effects were identified. Interestingly, a male proband with a deletion spanning the coding sequence of BGN and the 5’ untranslated region of the downstream gene (ATP2B3) presented with a more severe skeletal phenotype. This may possibly be explained by expressional activation of the downstream ATPase ATP2B3 (normally repressed in skin fibroblasts) driven by the remnant BGN promotor. This study highlights that aneurysms and dissections in MRLS extend beyond the thoracic aorta, affecting the entire arterial tree, and cardiovascular symptoms may coincide with non-specific connective tissue features. Furthermore, the clinical presentation is more severe and penetrant in males compared to females. Extensive analysis at RNA, cDNA, and/or protein level is recommended to prove a loss-of-function effect before determining the pathogenicity of identified BGN missense and non-canonical splice variants. In conclusion, distinct mechanisms may underlie the wide phenotypic spectrum of MRLS patients carrying loss-of-function variants in BGN.

Structural Features of Connective Tissue Formed around Resin Implants Subcutaneously Embedded in Dairy Cows

Foreign body reactions (FBRs) are inadvertently observed in invading or artificially embedded materials, triggering inflammation and subsequent fibrotic processes to occur in situ. Here, we assessed the spatiotemporal formation of connective tissue around implanted materials to establish a technique using connective tissue formed by FBRs as xenografts. An acrylic resin implant, comprising a columnar inner rod and a tubular outer cylinder (OC) with several slits, was embedded in adult dairy cows. Tissues formed in the inner rod and OC groups were histologically analyzed at weeks 2, 4, 8, and 12. Edematous tissues with non-collagenous fibers formed for 2 weeks and showed increased cellularity after 4 weeks. The weight, thickness, amounts of total protein, collagen, DNA, and quantitative scores of α-smooth muscle actin-positive myofibroblasts or elastic fibers notably increased after 8 weeks, with condensed collagen fibers showing orientation. Inflammatory cells were primarily localized in tissues close to the OC, and their numbers increased, with the count of CD204+ cells peaking at 8 weeks and declining at 12 weeks. The count of Ki67+ proliferating cells slightly increased in tissues close to the OC; however, the number and lumen of CD31+ vessels increased. These results may help understand FBR-related tissue remodeling.

Minireview of connective tissue features and selected forearm structures

Abstract Connective tissue is an extremely divaricated structure and, unlike other tissues, made up of proteins combined in various configurations. This construction is characterized by high variability and the ability to adapt through the appropriate selection of synthesized matrix components. That feature helps properly stabilize the body’s joints. The content of receptors enables information transfer about stimuli acting on itself and on neighboring structures. This work aims are to collect information about selected forearm structures, its features, functions and receptors content. One of the objectives is to improve the knowledge organization, indicate possible areas to expand and to inspire exploration diversity of connective tissue. Structures described in the article include the transverse carpal ligament, the superficial and deep fascia of the forearm, the interosseous membrane, the flexor retinaculum system and the palmar aponeurosis. These structures are well-known even to inexperienced science students. However, acquired knowledge is still incomplete and possible to explore.

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.

Organization of the Fibrous Component of Connective Tissue Paraneural Structures in Different Periods of Ontogenesis

Background: The steady increase in road traffic accidents, seasonal injuries leading to damage to the peripheral nerves of the extremities, as well as the military conflicts that are becoming more frequent now actualize research aimed at improving the diagnosis, treatment, and prevention of post-traumatic changes in the nerve trunks of the extremities. The frequency of peripheral nerve injuries varies from 1.5% to 13% of all injuries in peacetime; and during hostilities, it reaches 20%, and disability is 60%. At the same time, specific destructive changes in the nerves of the extremities after their traumatic injury require extraordinary organizational, therapeutic, and functional approaches to their restoration. The purpose of this study was to evaluate the dynamics of changes in the fibrous component of the paraneurium connective tissue structures in different periods of ontogenesis. Methods and Results: The study consisted of two stages. At the first stage, to study changes in the paraneurium connective tissue of the sciatic nerve (SN) in vivo, ultrasound was performed using an RS85 ultrasound scanner (Samsung Medison, South Korea, 2021) and two linear transducers, LA4-18B and LA2-9A. The thickness of the SN and the surrounding paraneurium were measured, and their structural organization was evaluated. The inclusion criterion was the absence of pathology from the peripheral nervous system. All subjects were divided into four age groups (15 people in each group): Group 1 (0-11 years), Group 2 (12-25 years), Group 3 (26-40 years), and Group 4 (41-60 years). The second stage was performed on cadaveric material of the paraneurium connective tissue of the SN of persons of both sexes, of different ages, whose cause of death was not related to diseases or injuries of the nervous system. To determine the qualitative and quantitative ratio of collagen fibers of different degrees of maturity in the connective tissue structures of the paraneurium tissue of the sciatic nerve, polarization microscopy (MicMed-6, Lomo, Russia) was applied, and the basic principle of double refraction, which in combination with Sirius red staining, made it possible to differentiate types I and III collagen. The amount of each collagen type was determined by analyzing the color gamut after Sirius red staining in polarizing light. Fibers containing type I collagen had a red glow, while those containing type III collagen had a green glow. The ratio of collagen types was calculated using the Fiji program (USA, 2022). US examination revealed the presence of a non-pronounced bilateral asymmetry in the structural organization of the paraneurium and an increase in the thickness of the SN with age, from 0-11 years to the age group of 41-60 years. Polarization microscopy of micro-preparations of the human sciatic nerve with paraneurium structures made it possible to analyze the density of the fibers of the paraneurium connective tissue and identify types I and III of collagen. At the age of 11, the amount of type I collagen fibers was maximum (69.74±0.41%), and type III collagen fibers amounted to 30.26±0.44%. Further, with increasing age, the amount of collagen III significantly diminished. The ratio of type I to type III collagen increased with patient age, with the highest ratio in the age group 41-60 years. Conclusion: The revealed dynamics of changes are quite comparable with the age-related features of connective tissue since it is this tissue that makes up the morphological substrate of the paraneurium of the sciatic nerve.

Association between Expression of Connective Tissue Genes and Prostate Cancer Growth and Progression.

To find an association between genomic features of connective tissue and pejorative clinical outcomes on radical prostatectomy specimens. We performed a retrospective analysis of patients who underwent radical prostatectomy and underwent a Decipher transcriptomic test for localized prostate cancer in our institution (n = 695). The expression results of selected connective tissue genes were analyzed after multiple t tests, revealing significant differences in the transcriptomic expression (over- or under-expression). We investigated the association between transcript results and clinical features such as extra-capsular extension (ECE), clinically significant cancer, lymph node (LN) invasion and early biochemical recurrence (eBCR), defined as earlier than 3 years after surgery). The Cancer Genome Atlas (TCGA) was used to evaluate the prognostic role of genes on progression-free survival (PFS) and overall survival (OS). Out of 528 patients, we found that 189 had ECE and 27 had LN invasion. The Decipher score was higher in patients with ECE, LN invasion, and eBCR. Our gene selection microarray analysis showed an overexpression in both ECE and LN invasion, and in clinically significant cancer for COL1A1, COL1A2, COL3A1, LUM, VCAN, FN1, AEBP1, ASPN, TIMP1, TIMP3, BGN, and underexpression in FMOD and FLNA. In the TCGA population, overexpression of these genes was correlated with worse PFS. Significant co-occurrence of these genes was observed. When presenting overexpression of our gene selection, the 5-year PFS rate was 53% vs. 68% (p = 0.0315). Transcriptomic overexpression of connective tissue genes correlated to worse clinical features, such as ECE, clinically significant cancer and BCR, identifying the potential prognostic value of the gene signature of the connective tissue in prostate cancer. TCGAp cohort analysis showed a worse PFS in case of overexpression of the connective tissue genes.

FIRE IN THE HOLE: GIANT BULLOUS LUNG DISEASE IN A VETERAN WITH BURN PIT EXPOSURE AND SMOKING

FIRE IN THE HOLE: GIANT BULLOUS LUNG DISEASE IN A VETERAN WITH BURN PIT EXPOSURE AND SMOKING

P27 Challenging management of GI complications in Systemic Sclerosis

Introduction/BackgroundSystemic sclerosis is a chronic, progressive, multisystemic autoimmune disease in which there is excessive collagen deposition in the dermis and internal organs. It is commonly categorized into limited cutaneous or diffuse cutaneous systemic sclerosis. In more than 80% of patients there is GI involvement. Gut complications can impair oral intake, absorption and even faecal continence, and consequently can have severe adverse effect on quality of life. With disease progression, management of GI symptoms may become more of a challenge. We present a challenging case of SSs with esophageal involvement along with severe regurgitation who eventually responded to a specific prokinetic.Description/Method70 y/o female initially presented to gastroenterology clinic in 2013 due to dysphagia to solids and was found to have benign fibrotic oesophageal stricture for which she had therapeutic dilatation, (normal biopsy result). Subsequently, she had barium swallow which showed severe regurgitation. Manometry confirmed severely hypo-contractile oesophagus thus she was referred to rheumatology for suspected connective tissue disorder.On initial review, she did not describe typical inflammatory symptoms, scleroderma, sclerodactyly, Raynaud’s phenomenon, digital ulcers, calcinosis, telangiectasia or any other connective tissue features but was diagnosed with limited cutaneous systemic sclerosis due to ANA & anti-centromere antibody positivity, severe oesophageal dysmotility and diagnosis of mild pulmonary hypertension (on right heart catheter studies).Her main disabling SSs symptom was refractory belching, intermittent dysphagia and reflux disease resulting in poor oral intake and resultant malnutrition. She had 4-week trial of antibiotics to treat for presumptive small intestine bacterial overgrowth (SIBO) due to persistent belching but had no evident improvement. She had multiple endoscopies which only showed grade B oesophagitis due to which she remained on high dose PPI (Omeprazole 40mg BD) but showed no recurrent stricture. She was also given dual therapy with Ranitidine 150mg bd but derived no benefit.In Rheumatology clinic she was started on erythromycin 250 mg BD as a pro-kinetic and in liquid form for better tolerability (due to the dysphagia) with gradual but significant improvement of her upper GI symptoms. Switching liquid form to tablets/capsule form via GP resulted in worsening symptoms so was switched back to liquid form. GI symptoms worsened again in 2017 and impression was tachyphylaxis to erythromycin. She was started on trial of another pro-kinetic (metoclopramide) but symptoms continued worsening. In view of this she was started back on liquid erythromycin and her symptoms gradually improved again and has remained stable since.Discussion/ResultsSystemic sclerosis (SSc) is an incurable connective tissue disorder. It is estimated that approximately 90% of patients with SSc have some form of oesophageal involvement. For first three years, this patient’s main symptoms were her upper GI tract issues with reflux and oesophageal dysmotility causing delayed gastric emptying.Considering the severity of her GI symptoms, it was of great importance for her to maintain a regular follow up with gastroenterology team for a regular review of symptoms and repeat investigations as needed such as multiple repeat UGI endoscopy to ensure no recurrence of oesophageal stricture, monitoring of GORD, and hydrogen breath testing.We recommend for patients with severe oesophageal dysmotility to be started on prokinetics early to control GI symptoms and have minimal impact of these on quality of life. Liquid preparation has shown a significant improvement in symptoms in our patient as compared to tablet or capsule form which actually worsened the symptoms.Key learning points/ConclusionDysphagia can be a presenting symptom of systemic sclerosis in some cases. Upper gastro-intestinal symptoms can be severe with significant effect on quality of life.Management of these symptoms can be challenging and may require a combination of treatments.Pro-kinetics mainly erythromycin can have a major positive impact in controlling GI symptoms,Liquid form had better outcome in this case as compared to tablet or capsule form.Poor control of GI symptoms can result in significant malnutrition which is associated with more aggressive disease progression, so GI symptoms management plays a key role in disease control.

Arterial tortuosity syndrome (variants in SLC2A10 gene) in two pediatric patients in the same city of Spain: a case report

BackgroundArterial tortuosity syndrome (ATS) (OMIM #208050) is a very rare autosomal recessive connective tissue disease characterized by elongation, tortuosity, and predisposition of aneurysms formation in medium and large-caliber arteries, vascular dissection, and ischemic events. To date, approximately 100 patients have been reported carrying some of the fewer than 35 causal mutations in the SLC2A10 gene.Case presentationHere we present the clinical and molecular characterization of two new Spanish pediatric ATS patients from two unrelated families in the same city in a short period of time. Due to the knowledge of the pathology through the first case this pathology was suspected from birth in the second case, requesting the directed genetic study.ConclusionIn addition to arterial tortuosity and connective tissue features, sequencing analysis revealed the homozygous and heterozygous Frameshift Deletion. Confirm diagnosis in the first few years of life is the most critical for possible life-threatening events and to offer adequate genetic counseling.

Pathogenetic features of experimental osteoarthrosis induced by dexamethasone and talc

The aim of the study was to investigate the pathogenesis of experimental osteoarthrosis induced by dexamethasone and talc by examining the structure and defining the morphometric and metabolic features of knee joint skeletal connective tissues in rats.Materials and methods. We performed a morphometric evaluation of articular cartilages (their thickness, extracellular matrix arrangement, spatial arrangement of the main components, distribution density, and main cellular indices of chondrocytes), as well as changes in subchondral bones (the presence of trabeculae in the basal layer of the articular cartilage and individual osteophytes) in 30 rats with a model of primary osteoarthrosis induced by sequential administration of 0.5 ml dexamethasone (2 mg) and 1 ml 10% sterile talc suspension mixed with normal saline into the joint cavity. We studied the histologic specimens of the knee joints stained with hematoxylin – eosin, Alcian blue (рН 1.0 and 2.5), as well as with Van Gieson’s, Masson’s, and Mallory’s trichome stains. The metabolic features of the articular cartilage and bone tissues were investigated by determining the hyaluronan, osteocalcin, and type I collagen levels in the serum of the rats.Results. In the rats with dexamethasone- and talc-induced osteoarthrosis, the thickness of cartilages in their weight-bearing areas decreased by 50%, the spatial arrangement of chondrocytes was impaired, and the nuclear – cytoplasmatic ratio (р < 0.01) decreased to 0.3. Besides, a rise in the serum levels of hyaluronan (p < 0.001) to 110.2 ng / ml, type I collagen fragments (p < 0.001) to 217.9 ng / ml, and osteocalcin (p < 0.001) to 231.1 ng / ml was detected.Conclusion. The main pathogenetic features of experimental osteoarthrosis induced by dexamethasone and talc include impaired distribution density, morphological characteristics, and functional activity of chondrocytes, which results in inhibited synthesis of extracellular matrix components in the articular cartilage and activated destruction of proteoglycans containing unsulphated glycosaminoglycans. The subchondral bone remodeling in experimental osteoarthrosis induced by dexamethasone and talc is characterized by intensification of synthetic activity of osteoblasts.

Quantitative Sound Speed Imaging of Cortical Bone and Soft Tissue: Results From Observational Data Sets.

This work presents the first quantitative ultrasonic sound speed images of ex vivo limb cross-sections containing both soft tissue and bone using Full Waveform Inversion (FWI) with level set (LS) and travel time regularization. The estimated bulk sound speed of bone and soft tissue are within 10% and 1%, respectively, of ground truth estimates. The sound speed imagery shows muscle, connective tissue and bone features. Typically, ultrasound tomography (UST) using FWI is applied to imaging breast tissue properties (e.g. sound speed and density) that correlate with cancer. With further development, UST systems have the potential to deliver volumetric operator independent tissue property images of limbs with non-ionizing and portable hardware platforms. This work addresses the algorithmic challenges of imaging the sound speed of bone and soft tissue by combining FWI with LS regularization and travel time methods to recover soft tissue and bone sound speed with improved accuracy and reduced soft tissue artifacts when compared to conventional FWI. The value of leveraging LS and travel time methods is realized by evidence of improved bone geometry estimates as well as promising convergence properties and reduced risk of final model errors due to un-modeled shear wave propagation. Ex vivo bulk measurements of sound speed and MRI cross-sections validates the final inversion results.

Quantifying Cell-Derived Changes in Collagen Synthesis, Alignment, and Mechanics in a 3D Connective Tissue Model.

Dysregulation of extracellular matrix (ECM) synthesis, organization, and mechanics are hallmark features of diseases like fibrosis and cancer. However, most in vitro models fail to recapitulate the three‐dimensional (3D) multi‐scale hierarchical architecture of collagen‐rich tissues and as a result, are unable to mirror native or disease phenotypes. Herein, using primary human fibroblasts seeded into custom fabricated 3D non‐adhesive agarose molds, a novel strategy is proposed to direct the morphogenesis of engineered 3D ring‐shaped tissue constructs with tensile and histological properties that recapitulate key features of fibrous connective tissue. To characterize the shift from monodispersed cells to a highly‐aligned, collagen‐rich matrix, a multi‐modal approach integrating histology, multiphoton second‐harmonic generation, and electron microscopy is employed. Structural changes in collagen synthesis and alignment are then mapped to functional differences in tissue mechanics and total collagen content. Due to the absence of an exogenously added scaffolding material, this model enables the direct quantification of cell‐derived changes in 3D matrix synthesis, alignment, and mechanics in response to the addition or removal of relevant biomolecular perturbations. To illustrate this, the effects of nutrient composition, fetal bovine serum, rho‐kinase inhibitor, and pro‐ and anti‐fibrotic compounds on ECM synthesis, 3D collagen architecture, and mechanophenotype are quantified.

#3085 Relationship between variant connective tissue (hypermobility) and autism sensory processing: externally oriented thinking as a mediator

Objectives/AimsAutism is a neurodevelopmental condition characterised by differences in sensory processing, social communication and restricted/repetitive behaviors. Joint hypermobility is a common connective tissue variant, reportedly overrepresented in Autism. Alexithymia is a personality construct characterised by altered emotional awareness which has notably high rates of overlap with autism spectrum disorder. This study tested whether hypermobility was associated with autistic traits and examined alexithymia as a mediator of this association.MethodForty-two people underwent eligibility assessment for a study of joint hypermobility and anxiety (ISRCTN17018615). Hypermobility was assessed using both the Brighton Criteria for Joint Hypermobilty Syndrome (JHS) and 2017 Hypermobile Ehlers Danlos Syndrome (hEDS) Criteria. Participants completed the Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS R: sensory/motor, language, social relatedness and circumscribed interest domains) to quantify autistic traits. No participant had a prior diagnosis of Autism. Participants also completed the Toronto Alexithymia Scale (TAS-20) to measure alexithymia. The TAS-20 has three domains: difficulty describing feelings, difficulty identifying feelings and externally oriented thinking.ResultsAll 42 participants met criteria for JHS, 26 participants also met criteria for hEDS. Strikingly, 22/42 (52.4%) scored above threshold for suspected Autism (26/42 in the sensory/motor domain; 22/42 in language domain; 22/42 in social relatedness domain; 17/42 in circumscribed interests domain). There were no significant differences in RAADS-R scores depending on hypermobility diagnosis. The number of connective tissue features (hEDS Criterion 2A) correlated with RAADS-R sensory/motor score (r = 0.418, p = 0.006) but not social relatedness nor circumscribed interests sub-scores. Full mediation of the relationship between the number of connective tissue features and RAADs sensory/motor score by TAS-20 externally oriented thinking was found using the method of Baron-Kenny (1986) and estimation of indirect effects (Hayes, 2018; bootstrapped confidence intervals (n = 5000, do not cross zero)). Difficulty identifying feelings and difficulty describing feelings domains did not mediate this relationship.ConclusionThese results add to evidence linking variant connective tissue to neurodevelopmental conditions (including Autism) and interestingly, specifically to sensory processing differences. Our study provides a strong rationale for screening for neurodevelopmental conditions in people with hypermobility and motivates further to understand symptom expression in this group. Our results also provide an insight into the processes underlying this relationship, which maybe important for informing interventions for people with hypermobility and autistic traits.

Williams syndrome.

Williams syndrome (WS) is a relatively rare microdeletion disorder that occurs in as many as 1:7,500 individuals. WS arises due to the mispairing of low-copy DNA repetitive elements at meiosis. The deletion size is similar across most individuals with WS and leads to the loss of one copy of 25-27 genes on chromosome 7q11.23. The resulting unique disorder affects multiple systems, with cardinal features including but not limited to cardiovascular disease (characteristically stenosis of the great arteries and most notably supravalvar aortic stenosis), a distinctive craniofacial appearance, and a specific cognitive and behavioural profile that includes intellectual disability and hypersociability. Genotype-phenotype evidence is strongest for ELN, the gene encoding elastin, which is responsible for the vascular and connective tissue features of WS, and for the transcription factor genes GTF2I and GTF2IRD1, which are known to affect intellectual ability, social functioning and anxiety. Mounting evidence also ascribes phenotypic consequences to the deletion of BAZ1B, LIMK1, STX1A and MLXIPL, but more work is needed to understand the mechanism by which these deletions contribute to clinical outcomes. The age of diagnosis has fallen in regions of the world where technological advances, such as chromosomal microarray, enable clinicians to make the diagnosis of WS without formally suspecting it, allowing earlier intervention by medical and developmental specialists. Phenotypic variability is considerable for all cardinal features of WS but the specific sources of this variability remain unknown. Further investigation to identify the factors responsible for these differences may lead to mechanism-based rather than symptom-based therapies and should therefore be a high research priority.

Bi-allelic premature truncating variants in LTBP1 cause cutis laxa syndrome

Latent transforming growth factor β (TGFβ)-binding proteins (LTBPs) are microfibril-associated proteins essential for anchoring TGFβ in the extracellular matrix (ECM) as well as for correct assembly of ECM components. Variants in LTBP2, LTBP3, and LTBP4 have been identified in several autosomal recessive Mendelian disorders with skeletal abnormalities with or without impaired development of elastin-rich tissues. Thus far, the human phenotype associated with LTBP1 deficiency has remained enigmatic. In this study, we report homozygous premature truncating LTBP1 variants in eight affected individuals from four unrelated consanguineous families. Affected individuals present with connective tissue features (cutis laxa and inguinal hernia), craniofacial dysmorphology, variable heart defects, and prominent skeletal features (craniosynostosis, short stature, brachydactyly, and syndactyly). Invitro studies on proband-derived dermal fibroblasts indicate distinct molecular mechanisms depending on the position of the variant in LTBP1. C-terminal variants lead to an altered LTBP1 loosely anchored in the microfibrillar network and cause increased ECM deposition in cultured fibroblasts associated with excessive TGFβ growth factor activation and signaling. In contrast, N-terminal truncation results in a loss of LTBP1 that does not alter TGFβ levels or ECM assembly. Invivo validation with two independent zebrafish lines carrying mutations in ltbp1 induce abnormal collagen fibrillogenesis in skin and intervertebral ligaments and ectopic bone formation on the vertebrae. In addition, one of the mutant zebrafish lines shows voluminous and hypo-mineralized vertebrae. Overall, our findings in humans and zebrafish show that LTBP1 function is crucial for skin and bone ECM assembly and homeostasis.

Ultrastructural features of the double capsulated connective tissue around silicone prostheses.

The implantation of breast prostheses for both aesthetic and reconstructive purposes has been growing exponentially in the last 20 years. Safety and prosthesis lifespan are majorly debated issues in relation to the correlated long-term complications. Mainly the periprosthetic capsule that develops around the implant is often the cause of complications and particularly for macrotextured silicone breast implants. Some reports have tried to elucidate the mechanism by which macrotextured silicone implants undergo damage and cause double capsule formation. In this study, we investigated the morphological characteristics of double capsule of macrotextured implants surgically removed from patients. With the use of microscopy techniques, this work analyzed the newly formed tissue observed in the interaction between synthetic and biological surfaces.

Биопсия кожи как метод определения показаний к превентивному эндопротезированию передней брюшной стенки

The aim is to examine the effectiveness of preoperative skin biopsy method to determine indications for preventive endoprosthesis implantation of the anterior abdominal wall based on structural features of connective tissue. Materials and methods. The study included 17 patients who had been planned to undergo a scheduled surgery such as video laparoscopic cholecystectomy. The histological material was collected with DERMO PUNCH biopsy needles in an outpatient clinic. Using polarized light microscopy we inspected histological slices coloured with Sirius red. After that we analyzed histological sections including the ratio of collagen fibers, the density of connective tissue and the number of interfibrous spaces. Results. All the studied features of connective tissue dysplasia had been registered among 18% of patients; significant differences (p ≤0.05) had been identified among other 24% of patients. In patients with identified signs of connective tissue dysplasia, an increase in type III collagen fibers and a decrease in type I fibers were revealed, which directly resulted in a decrease in their ratio. In addition, this category of patients noted a decrease in the density of connective tissue and a significant number of interfibrous spaces. Conclusion. Skin biopsy is a safe and informative method to reveal patients with predisposition to the formation of hernias of the anterior abdominal wall based on structural features of connective tissue and to determine indications for preventive endoprosthetic implantation. This method will reduce the frequency of postoperative ventral hernias, so the effectiveness of the treatment will definitely increase.

Visible and Near-Infrared Multispectral Features in Conjunction with Artificial Neural Network and Partial Least Squares for Predicting Biochemical and Micro-Structural Features of Beef Muscles.

The objective of this study was to determine the potential of multispectral imaging (MSI) data recorded in the visible and near infrared electromagnetic regions to predict the structural features of intramuscular connective tissue, the proportion of intramuscular fat (IMF), and some characteristic parameters of muscle fibers involved in beef sensory quality. In order to do this, samples from three muscles (Longissimus thoracis, Semimembranosus and Biceps femoris) of animals belonging to three breeds (Aberdeen Angus, Limousine, and Blonde d’Aquitaine) were used (120 samples). After the acquisition of images by MSI and segmentation of their morphological parameters, a back propagation artificial neural network (ANN) model coupled with partial least squares was applied to predict the muscular parameters cited above. The results presented a high accuracy and are promising (R2 test > 0.90) for practical applications. For example, considering the prediction of IMF, the regression model giving the best ANN model exhibited R2P = 0.99 and RMSEP = 0.103 g × 100 g−1 DM.

P09 Audit of anti-nuclear antibody testing in East Kent and the British Society for Rheumatology Choosing Wisely recommendations

Abstract Background The British Society for Rheumatology has recently issued Choosing Wisely guidance on ANA testing, to avoid unnecessary testing and inappropriate use of resources. Currently there are no local guidelines on ANA testing. The aim of this audit was to use the BSR guidance as best practice to assess current local testing and then develop guidelines. The standards assessed were as follows: testing ANA should be reserved for patients suspected to have a diagnosis of a connective tissue disease, e.g. lupus. Testing ANA should be avoided in the investigation of widespread pain or fatigue alone. Repeat testing is not normally indicated unless the clinical picture changes significantly. Methods Retrospective data collection of ANA requests at East Kent Hospitals University & Foundation Trust was extracted from the pathology IT system (Apex) from January to March 2019. The clinical indications entered for electronic requesting were recorded. All ANA requests were recorded as ‘appropriate’, ‘inappropriate’ or having ‘insufficient documentation’. A request was considered appropriate if it documented one of the following indications/suspected diagnoses: inflammatory arthritis, connective tissue features - Raynaud’s, vasculitis/photosensitive rash, scleroderma, clinical myositis, autoimmune haemolytic anaemias, cytopenia, Suspected autoimmune liver disease, pleurisy, pulmonary fibrosis, pericarditis, serositis, autoimmune renal disease, autoimmune neurologic disease, BILAG registered patients, patients on/requiring biologics. All other requests which did not meet these standards were considered inappropriate. Results There were 1,517 requests made in 3 months; 180 requests (11.86%) were positive and 1,337 (88.14%) were negative. 61% of ANA requests were from outpatients, 25% were inpatient requests and 14% were requests from GPs. Outpatients requests: neurology, rheumatology, gastroenterology, respiratory and renal medicine (in order of frequency). Only 17% of requests met the set standards; 41% were inappropriate requests and 42% were requests with insufficient details. Conclusion ANA testing is relatively expensive compared to other routine screening tests. The assay is time consuming and labour-intensive, and due to the volume of requests made, 2 batches are tested daily in East Kent. With only 17% of the 1,517 tests meeting the standards, this suggests the majority were inappropriately requested. There were >15,000 requests from East Kent and nearby trusts from April 2018 to December 2018. At £2.50 per test, adhering to guidelines could save potentially £12,000 per year. Local guidelines have now been devised based on the Choosing Wisely standards, indications & suspected diagnoses documented. ANA testing will be re-audited in 6 months. Disclosures S. Rasool None. K. Beharry None. A. Afifi None. F. Shahzad None. R. mahadi None. D. De Lord None.

Insights into the molecular pathogenesis of cardiospondylocarpofacial syndrome: MAP3K7 c.737-7A > G variant alters the TGFβ-mediated α-SMA cytoskeleton assembly and autophagy

Transforming growth factor beta-activated kinase 1 (TAK1) is a highly conserved kinase protein encoded by MAP3K7, and activated by multiple extracellular stimuli, growth factors and cytokines. Heterozygous variants in MAP3K7 cause the cardiospondylocarpofacial syndrome (CSCFS) which is characterized by short stature, dysmorphic facial features, cardiac septal defects with valve dysplasia, and skeletal anomalies. CSCFS has been described in seven patients to date and its molecular pathogenesis is only partially understood. Here, the functional effects of the MAP3K7 c.737-7A > G variant, previously identified in a girl with CSCFS and additional soft connective tissue features, were explored. This splice variant generates an in-frame insertion of 2 amino acid residues in the kinase domain of TAK1. Computational analysis revealed that this in-frame insertion alters protein dynamics in the kinase activation loop responsible for TAK1 autophosphorylation after binding with its interactor TAB1. Co-immunoprecipitation studies demonstrate that the ectopic expression of TAK1-mutated protein impairs its ability to physically bind TAB1. In patient's fibroblasts, MAP3K7 c.737-7A > G variant results in reduced TAK1 autophosphorylation and dysregulation of the downstream TAK1-dependent signaling pathway. TAK1 loss-of-function is associated with an impaired TGFβ-mediated α-SMA cytoskeleton assembly and cell migration, and defective autophagy process. These findings contribute to our understanding of the molecular pathogenesis of CSCFS and might offer the rationale for the design of novel therapeutic targets.