Luminal Surface Research Articles

Distribution of 5HT receptors during the regeneration process after spinal cord transection in goldfish

Spinal cord injury in teleosts leads to a fibrous scar, but axons sometimes spontaneously regenerate beyond the scar. In goldfish, regenerating axons enter the scar through tubular structures and enlargement of the tubular diameter is proportional to the increase in the number of regenerating axons. During the regeneration process, mast cells containing 5-hydroxytryptamine (5HT) are recruited to the injury site, and 5HT neurons are newly generated. Here, we investigated the distribution of 5HT receptors during this process to determine their role in remodeling the fibrous scar and tubular structures. At 2 weeks after spinal cord transection (SCT) in goldfish, expression of the 5HT2A and 5HT2C receptor subtypes was observed in the ependymo-radial glial cells lining the central canal of the spinal cord. 5HT2A was expressed at the luminal surface, suggesting that it is receptive to 5HT in the cerebrospinal fluid. 5HT2C, on the other hand, was expressed around the nuclei and in the radial processes protruding from the basal surface, suggesting that it is receptive to 5HT released from nearby nerve endings. 5HT2C was also expressed in the fibrous scar where mast cells containing 5HT were abundant. 5HT1B expression was coincident with the basement membrane bordering the fibrous scar and the surrounding nervous tissue, and with the basement membrane of the tubular structure through which axons pass during regeneration. Our findings suggest that multiple 5HT receptors are involved in remodeling the injured site during the regenerative process following SCT. Ependymo-radial glial cells expressing 5HT2A and 5HT2C are involved in neurogenesis and gliogenesis, which might contribute to remodeling the fibrous scar in coordination with 5HT-containing mast cells. Coincident expression of 5HT1B with the basement membrane might be involved in remodeling the tubular structures, thereby promoting axonal regeneration.

Luminal Surface Plasma Treatment of Closed Cylindrical Microchannels: A Tool toward the Creation of On-Chip Vascular Endothelium.

On-chip vascular microfluidic models provide a great tool to study aspects of cardiovascular diseases in vitro. To produce such models, polydimethylsiloxane (PDMS) has been the most widely used material. For biological applications, its hydrophobic surface has to be modified. The major approach has been plasma-based surface oxidation, which has been very challenging in the case of channels enclosed within a microfluidic chip. The preparation of the chip combined a 3D-printed mold with soft lithography and commonly available materials. We have introduced the high-frequency low-pressure air-plasma surface modification of seamless channels enclosed within a PDMS microfluidic chip. The plasma treatment modified the luminal surface more uniformly than in previous works. Such a setup enabled a higher degree of design freedom and a possibility of rapid prototyping. Further, plasma treatment in combination with collagen IV coating created a biomimetic surface for efficient adhesion of vascular endothelial cells as well as promoted long-term cell culture stability under flow. The cells within the channels were highly viable and showed physiological behavior, confirming the benefit of the presented surface modification.

Epithelial sodium channel (ENaC) in GtoPdb v.2023.1

Epithelial sodium channel (ENaC) in GtoPdb v.2023.1

SLC36 family of proton-coupled amino acid transporters in GtoPdb v.2023.1

Members of the SLC36 family of proton-coupled amino acid transporters are involved in membrane transport of amino acids and derivatives [29, 30]. The four transporters show variable tissue expression patterns and are expressed in various cell types at the plasma-membrane and in intracellular organelles. PAT1 is expressed at the luminal surface of the small intestine and absorbs amino acids and derivatives [4]. In lysosomes, PAT1 functions as an efflux mechanism for amino acids produced during intralysosomal proteolysis [2, 26]. PAT2 is expressed at the apical membrane of the renal proximal tubule [7] and at the plasma-membrane in brown/beige adipocytes [31]. PAT1 and PAT4 are involved in regulation of the mTORC1 pathway [12, 28]. More comprehensive lists of substrates can be found within the reviews under Further Reading and in the references [3].

Development of novel layered polyglycolic acid sheet for regeneration of critical-size defect in rat trachea.

Polyglycolic acid (PGA) sheets are difficult to adapt to the central airway because of poor durability against high air pressure. Therefore, we developed a novel layered PGA material to cover the central airway and examined its morphologic traits and functional performance as a potential tracheal replacement. A critical-size defect in rat cervical tracheas was covered with the material. Morphologic changes were bronchoscopically and pathologically evaluated. Functional performance was evaluated by regenerated ciliary area, ciliary beat frequency and ciliary transport function determined by measuring the moving distance of microspheres dropped onto the trachea (µm/s). The evaluation time points were 2 weeks, 1 month, 2 months and 6 months after surgery (n = 5, respectively). Forty rats underwent implantation, and all survived. Histological examination confirmed ciliated epithelization on the luminal surface after 2 weeks. Neovascularization was observed after 1 month, tracheal glands after 2 months and chondrocyte regeneration after 6 months. Although the material was gradually replaced by self-organization, tracheomalacia was not bronchoscopically observed at any time point. The area of regenerated cilia significantly increased between 2 weeks and 1 month (12.0% vs 30.0%; P = 0.0216). The median ciliary beat frequency significantly improved between 2 weeks and 6 months (7.12 vs 10.04 Hz; P = 0.0122). The median ciliary transport function was significantly improved between 2 weeks and 2 months (5.16 vs 13.49 µm/s; P = 0.0216). The novel PGA material showed excellent biocompatibility and tracheal regeneration both morphologically and functionally 6 months after tracheal implantation.

Small-Caliber Tissue-Engineered Vascular Grafts Based on Human-Induced Pluripotent Stem Cells: Progress and Challenges.

Small-caliber tissue-engineered vascular grafts (TEVGs, luminal diameter <6 mm) are promising therapies for coronary or peripheral artery bypassing surgeries or emergency treatments of vascular trauma, and a robust seed cell source is required for scalable manufacturing of small-caliber TEVGs with robust mechanical strength and bioactive endothelium in future. Human-induced pluripotent stem cells (hiPSCs) could serve as a robust cell source to derive functional vascular seed cells and potentially lead to generation of immunocompatible engineered vascular tissues. Up to date, this rising field of small-caliber hiPSC-derived TEVG (hiPSC-TEVG) research has received increasing attention and achieved significant progress. Implantable, small-caliber, hiPSC-TEVGs have been generated. These hiPSC-TEVGs displayed rupture pressure and suture retention strength approaching to those of human native saphenous veins, with vessel wall decellularized and luminal surface endothelialized with monolayer of hiPSC-endothelial cells. Meanwhile, a series of challenges remain in this field, including functional maturity of hiPSC-derived vascular cells, poor elastogenesis, suboptimal efficiency of obtaining hiPSC-derived seed cells, and relative low ready availability of hiPSC-TEVGs, which are waiting to be addressed. This review is conceived to introduce representative achievements and challenges in small-caliber TEVG generation using hiPSCs, and encapsulate the potential solution and future directions.

Ultrasonic measurement of carotid luminal surface roughness with removal of axial displacement caused by blood pulsation

For early diagnosis of atherosclerosis, we have developed a method to measure the initial minute surface roughness utilizing the natural longitudinal displacement of the intima-media-complex (IMC) on the carotid artery caused by pulsation. However, the IMC displaces not only in the longitudinal direction but also in the axial direction due to the pulsation. In the present paper, we proposed a novel method to remove the pulsation component by spatially convolving a high-pass filter with the measured depths of IMC in the longitudinal direction. The proposed method was validated by a phantom experiment, and the surface roughness with ten saw teeth was correctly measured. Next, the surface roughness of the carotid artery wall was measured for two healthy volunteers. The proposed method reduced the variation of measured surface roughness among beams compared to the previous method.

Stem cells in the context of colon carcinogenesis (a literature review)

Aim. To analyze the latest literature data on stem cells in general, intestinal stem cells in particular, as well as cancer stem cells in the context of colon carcinogenesis. Over the past decade, a significant amount of data confirming the existence of cancer stem cells, their importance in cancer progression, resistance to current treatment regimens, and the occurrence of relapses has been accumulated. These cells are a small fraction of cancer cells that initiate tumor growth and provide tumor tissue heterogeneity. In addition, these cells are distinguished by a significant resistance to effects of various cytotoxic factors. Therefore, the possibility of isolating cancer stem cells and further targeted action are highly important for enabling a complete tumor eradication. A study on intestinal stem cells has always been in the focus of stem cell biology researchers’ attention because intestinal stem cells are an example of an active cell population that provides regular rapid renewal of the epithelium, which is constantly exposed to toxic, bacterial, and other aggressive factors. Accordingly, colon carcinogenesis is a convenient model for studying the role of stem cells in tumorigenesis. At the same time, there are two main current schemes of colon carcinogenesis, which are acknowledged – these are so-called “bottom-up” and “top-down” modes of transformed cell spreading. The “bottom-up” scheme was substantiated first, proving to be in good agreement with modern ideas about the structure of intestinal crypts. However, a little later, reports about the possibility of the “top-down” direction began to appear: differentiated cells located in the superficial parts of the intestinal crypts, undergoing mutations, could dedifferentiate and return to the basal parts; a pathological increase in the surface epithelial cells proliferation level was possible as well, leading to an increase in the luminal surface area, formation of grooves mimicking the intestinal crypts. This review provides the latest data on stem cells in general, in particular on intestinal stem cells, as well as on cancer stem cells in the context of colon carcinogenesis. We also analyze the latest literature data on the possibility of isolating cancer stem cells in colon carcinomas using molecular markers, difficulties associated with this process, and issues that are still unresolved. Conclusions. Today, there is no doubt about the existence and importance of cancer stem cells in carcinomas. Quite a lot of molecular markers of cancer stem cells have been identified and studied. It is worth noting that certain aspects of cancer stem cells can not be studied one-sidedly but require a multidimensional analysis.

Evaluation of cold atmospheric plasma for the decontamination of flexible endoscopes

Despite adherence to standard protocols, residues including live microorganisms may remain on the various surfaces of reprocessed flexible endoscopes. Prions are infectious proteins notoriously difficult to eliminate. We tested the potential of cold atmospheric plasma (CAP) for the decontamination of flexible endoscope various surfaces, measuring total proteins and prion-residual infectivity as an indicator of efficacy. New PTFE endoscope channels and metal test surfaces spiked with test soil or prion-infected tissues were treated using different CAP-generating prototypes. Surfaces were then examined for the presence of residues using very sensitive fluorescence epi-microscopy. Prion residual infectivity was determined using the wire implant animal model and a new, more sensitive cell infectivity assay. A CAP jet applied perpendicularly at close range on flat test surfaces removed soil within 3 minutes but left microscopic residues and failed to eliminate prion infectivity according to the wire implant animal assay. The longitudinal gas flow from CAP prototypes developed for the treatment of long channels led to the displacement and sedimentation of residual soil towards the distal end, when applied alone. Observations of the plasma inside glass tubes showed temporal and spatial heterogeneity within a limited range. After standard enzymatic manual pre-wash, "CAP-activated" gas effluents prevented prion transmission from treated endoscope channels according to our prion infectivity cell assay. CAP shows promising results as a final step for surgical surfaces decontamination. Optimising CAP delivery could further enhance CAP efficacy, offering a safe, chemical-free alternative for the reprocessing of all luminal flexible endoscope surfaces.

Ultrasonic measurement of thickness of carotid arterial wall using its natural longitudinal displacement

The thickness of the carotid arterial wall obtained from B-mode imaging using ultrasonic diagnostic devices is widely used for the diagnosis of atherosclerosis. However, the measurement interval in the lateral direction of the B-mode image depended on the beam interval (>100 μm). Therefore, the B-mode image is discrete in the lateral direction and cannot reflect changes in local and minute thicknesses. A method for measuring the roughness of the luminal surface of the wall was proposed using the displacement of the carotid arterial wall in the lateral direction during one heartbeat. In this method, the lateral measurement interval is much shorter than the beam interval, enabling a smooth measurement of the luminal surface. By simultaneously applying the method to the lumen-intima and medial-adventitia boundaries of the wall, we propose a novel method to measure the local and minute thicknesses of the carotid arterial wall.

Urinary Glycosaminoglycans Are Associated with Recurrent UTI and Urobiome Ecology in Postmenopausal Women

Glycosaminoglycans (GAGs) are linear, negatively charged polysaccharides composed of repeating disaccharide units of uronic acid and amino sugars. The luminal surface of the bladder epithelium is coated with a GAG layer. These urothelial GAGs are thought to provide a protective barrier and serve as a potential interaction site with the urinary microbiome (urobiome). Previous studies have profiled urinary GAG composition in mixed cohorts, but the urinary GAG composition in postmenopausal women remains undefined. To investigate the relationship between GAGs and recurrent urinary tract infection (rUTI), we profiled urinary GAGs in a controlled cohort of postmenopausal women. We found that chondroitin sulfate (CS) is the major urinary GAG in postmenopausal women and that urinary CS was elevated in women with active rUTI. We also associated urinary GAGs with urobiome composition and identified bacterial species that significantly associated with urinary GAG concentration. Corynebacterium amycolatum, Porphyromonas somerae, and Staphylococcus pasteuri were positively associated with heparin sulfate or hyaluronic acid, and bacterial species associated with vaginal dysbiosis were negatively correlated with urinary CS. Altogether, this work defines changes in urinary GAG composition associated with rUTI and identifies new associations between urinary GAGs and the urobiome that may play a role in rUTI pathobiology.

Bio-inspired robust, superhydrophilic and superlubric artificial vascular endothelium coating for anti-thromboinflammation on blood-contacting devices

Thromboinflammation remains a substantial challenge that could compromise the therapeutic success of blood-contacting medical devices in clinic. Herein, we proposed a bioinspired strategy of constructing artificial vascular endothelium coating (AVEC) to block thromboinflammation, whereby sulfobetaine-based zwitterionic hydrogel was reinforced by multiple hydrogen bonds and covalently attached to the surface of blood-contacting medical catheters to recapitulate the physiological structure, mechanical character and biophysical function of endothelium. The cobblestone-like surface topographical structures of AVEC demonstrated superhydrophilicity (contact angle = 6.9°) and superlubricity (friction coefficient = 0.0017), which enabled a blood-unperturbed bioinert feature characterized by totally anti-adhesion of blood components, avoiding activation of complement system and platelets, and classical polarization of macrophages, finally inhibiting the thromboinflammatory reaction. Moreover, the multiple hydrogen bonds reinforced, covalently crosslinked and attached AVEC showed superior mechanical robustness under blood flow shear (6 L/min), extrusion (40 r/min; 60 days) or bending deformation (2000 times). Antithrombogenic property of AVEC tested on extracorporeal circulation lines in the setting of hemodialysis and cardiopulmonary bypass surgery on porcine demonstrated no adhesion and activation of platelet on the luminal surface after circulation for 8 h, which was unequivocally comparable to the commercial heparinized Bioline® product. Further, the applicability of AVEC was verified on various clinically used blood-contacting catheters with short or long service time for different indications, where no thrombus was detected on peripherally inserted central catheter (PICC) after endovascular implantation for 7 days. Collectively, the AVEC should provide a novel, safe and generalized anti-thromboinflammation strategy for diverse blood-contacting medical devices.

Intracellular Membrane Transport in Vascular Endothelial Cells.

The main component of blood and lymphatic vessels is the endothelium covering their luminal surface. It plays a significant role in many cardiovascular diseases. Tremendous progress has been made in deciphering of molecular mechanisms involved into intracellular transport. However, molecular machines are mostly characterized in vitro. It is important to adapt this knowledge to the situation existing in tissues and organs. Moreover, contradictions have accumulated within the field related to the function of endothelial cells (ECs) and their trans-endothelial pathways. This has induced necessity for the re-evaluation of several mechanisms related to the function of vascular ECs and intracellular transport and transcytosis there. Here, we analyze available data related to intracellular transport within ECs and re-examine several hypotheses about the role of different mechanisms in transcytosis across ECs. We propose a new classification of vascular endothelium and hypotheses related to the functional role of caveolae and mechanisms of lipid transport through ECs.

Multilayered blow-spun vascular prostheses with luminal surfaces in Nano/Micro range: the influence on endothelial cell and platelet adhesion

BackgroundIn this study, two types of polyurethane-based cylindrical multilayered grafts with internal diameters ≤ 6 mm were produced by the solution blow spinning (SBS) method. The main aim was to create layered-wall prostheses differing in their luminal surface morphology. Changing the SBS process parameters, i.e. working distance, rotational speed, volume, and concentration of the polymer solution allowed to obtain structures with the required morphologies. The first type of prostheses, termed Nano, possessed nanofibrous luminal surface, and the second type, Micro, presented morphologically diverse luminal surface, with both solid and microfibrous areas.ResultsThe results of mechanical tests confirmed that designed prostheses had high flexibility (Young’s modulus value of about 2.5 MPa) and good tensile strength (maximum axial load value of about 60 N), which meet the requirements for vascular prostheses. The influence of the luminal surface morphology on platelet adhesion and the attachment of endothelial cells was investigated. Both surfaces did not cause hemolysis in contact with blood, the percentage of platelet-occupied area for Nano and Micro surfaces was comparable to reference polytetrafluoroethylene (PTFE) surface. However, the change in morphology of surface-adhered platelets between Nano and Micro surfaces was visible, which might suggest differences in their activation level. Endothelial coverage after 1, 3, and 7 days of culture on flat samples (2D model) was higher on Nano prostheses as compared with Micro scaffolds. However, this effect was not seen in 3D culture, where cylindrical prostheses were colonized using magnetic seeding method.ConclusionsWe conclude the produced scaffolds meet the material and mechanical requirements for vascular prostheses. However, changing the morphology without changing the chemical modification of the luminal surface is not sufficient to achieve the appropriate effectiveness of endothelialization in the 3D model.

Acellular Human Placenta Small-Diameter Vessels as a Favorable Source of Super-Microsurgical Vascular Replacements: A Proof of Concept.

In this study, we aimed to evaluate the human placenta as a source of blood vessels that can be harvested for vascular graft fabrication in the submillimeter range. Our approach included graft modification to prevent thrombotic events. Submillimeter arterial grafts harvested from the human placenta were decellularized and chemically crosslinked to heparin. Graft performance was evaluated using a microsurgical arteriovenous loop (AVL) model in Lewis rats. Specimens were evaluated through hematoxylin-eosin and CD31 staining of histological sections to analyze host cell immigration and vascular remodeling. Graft patency was determined 3 weeks after implantation using a vascular patency test, histology, and micro-computed tomography. A total of 14 human placenta submillimeter vessel grafts were successfully decellularized and implanted into AVLs in rats. An appropriate inner diameter to graft length ratio of 0.81 ± 0.16 mm to 7.72 ± 3.20 mm was achieved in all animals. Grafts were left in situ for a mean of 24 ± 4 days. Decellularized human placental grafts had an overall patency rate of 71% and elicited no apparent immunological responses. Histological staining revealed host cell immigration into the graft and re-endothelialization of the vessel luminal surface. This study demonstrates that decellularized vascular grafts from the human placenta have the potential to serve as super-microsurgical vascular replacements.

Abstract Number ‐ 97: Middle meningeal artery embolization to treat chronic subdural hematomas – Retrospective study of morphological parameters

Introduction Chronic subdural hematomas are a common neurovascular condition that involve the gradual and continual exudation of fluid from a compromised cell layer lining the dura [1]. Embolization of the middle meningeal artery (MMAE) results in lower recurrence rates as compared to traditional surgical burr hole evacuation [2‐4]. Liquid embolic agents such as cyanoacrylates or ethylene vinyl alcohol copolymers can potentially provide a distinct advantage with greater distal penetration resulting in faster hematoma resolution [5]. Their inherent radiopacity (after pre‐mixing) also allows for accurate visualization and control over embolization. The hypothesis of this study is that liquid embolic surface area would correlate with more effective cSDH volume resolution in patients. Methods Under IRB approval, we retrospectively analyzed non‐contrast head CTs and immediate post‐embolization flat‐detector CTs from 45 patients who underwent first‐line MMAE with a liquid embolic. Patients who received any neurosurgical intervention were excluded. 3D‐Slicer was used to segment and calculate hematoma volumes pre‐embolization, as well as at 1‐month, 3‐months, and 6‐months post‐embolization. The flat‐detector CT scans were also segmented to calculate the surface area of the liquid embolic. Results There was significant reduction in hematoma volume at 1‐, 3‐ and 6‐months with respect to the preoperative cSDH volume (Figure A, Pre: pre‐treatment, mo: month). The liquid embolic surface area significantly correlated with (a) pre‐embolization hematoma volume (R2 = 0.27, p = 0.0002, n = 45), (b) the reduction in volume at 1‐month post‐embolization (R2 = 0.16, p = 0.007, n = 41), (c) volume reduction at 3‐months post‐embolization (R2 = 0.29, p = 0.0015, n = 32), (d) hematoma volume resorption rate (cc/day) calculated at 1‐month post‐embolization (R2 = 0.16, p = 0.011, n = 39), and (e) hematoma volume resorption rate calculated at 3‐months post‐embolization (R2 = 0.34, p = 0.0003, n = 34, Figure B). The liquid embolic surface area was not correlated to the volume reduction at 6‐months (p = 0.3, n = 26). Conclusions The luminal surface area of MMA vasculature embolized with liquid embolics may be correlated to the reduction in cSDH volumes. The liquid embolic segmentation method used here needs further refinement to improve accuracy. Additional data sets are required to confirm the correlations reported here.

Abstract Number ‐ 127: Poly(vinyl alcohol) grafts of brain aneurysms with patient‐specific morphologies

Introduction Current animal models of brain aneurysms used for testing neuro‐interventional devices have highly simplistic vascular anatomy in comparison with human aneurysm‐parent vessel complexes. Poly(vinyl alcohol) (PVA) is a leading biomaterial for manufacture of artificial vascular grafts because of its biocompatibility, hemocompatibility, availability, low cost, moldability/castability, and tunable mechanical properties to match arterial compliance [1,2]. However, PVA is non‐cell adhesive and requires modification with additives to promote endothelialization of the luminal surface to maintain long‐term graft patency [1,3]. We have previously studied the biocompatibility of resorcinol bis(diphenyl phosphate) (RDP) coated clays blended with polymers and have found excellent cell adhesion and proliferation with human dermal fibroblasts as well as dental pulp stem cells [4]. Our overall goal is to develop a new in vivo model of brain aneurysms by manufacturing patient‐specific aneurysm anatomies with a blend of PVA and RDP clay and grafting them into animals. Here, we evaluate the casting of PVA in the shape of patient‐specific aneurysms. Methods 10% PVA (w/w) (99% hydrolyzed, 85–124K molecular weight, Sigma Aldrich) was dissolved in deionized water, to which 1% RDP clay (ICL Industrial Products, Be’er Sheva, Israel) was added. The PVA was crosslinked using 15% (w/w) of sodium trimetaphosphate and 30% (w/w) of sodium hydroxide, after which rheological studies (stress sweeps using a Bohlin Gemini rheometer) were conducted. In the casting procedure, negative molds of both simple tubes and complex aneurysm geometries were designed using Rhinoceros 3D software (Robert McNeel &amp; Associates, Seattle, WA) and 3D printed in ABS plastic. The negative mold was then filled with beeswax, resulting in a positive wax mold that was dip‐coated 8 times in PVA solution, and spun on a two‐axis spinner in between each dip to ensure even coverage. After overnight drying in a fume hood, the model was placed in heated water, allowing the wax to melt out and leaving behind the luminal PVA cast. Results Rheology on the crosslinked polymers showed that the PVA/RDP blend exhibited over twice the elastic modulus of unblended PVA (Figure A). Such enhanced mechanical properties are consistent with previous studies [5]. Both simple tubular geometries and patient‐specific anatomies were able to be successfully cast using the methodology developed here (Figure B). Conclusions This proposed casting methodology demonstrates a realistic, efficient way to replicate complex aneurysm geometries with comparatively inexpensive materials and short time frame. Future endeavors will include further exploration of the PVA/RDP biocompatibility as well as completing the casting procedure with a PVA/RDP blend.

Intimal growth on the luminal surface of arteriovenous grafts in rats.

Endothelial cells are known to grow on the luminal surface of arteriovenous grafts (AVGs) used in hemodialysis. Although endothelial cells are important for preventing infection, a detailed growth of endothelial cells in AVGs is unknown. This study sought to create a simpler animal model of AVGs and to investigate how endothelial cells form on the luminal surface. Polyethylene grafts were placed between the cervical artery and vein of Wistar rats. The grafts were removed at 6h, 24h, 3days, or 7days after placement. The luminal surface was observed under optical and polarizing microscopy and stained with endothelial cell markers (LEL, CD31), the progenitor cell marker CD34, and the macrophage marker ED-1. Microscopy demonstrated many diffuse vascular endothelial cells on the luminal surface of AVGs after placement. While there was no difference in the number of LEL-positive cells between the arterial side (AS) and venous side (VS) at 6h or 7days, there were significantly more of these cells on the VS at both 24h and 3days (p < 0.05). Analysis at 24h showed some CD31-positive cells and few CD34-positive cells. This was the first study to use a simple rat model of AVG placement. Endothelial cell formation was initially more active on the VS than on the AS, but these cells subsequently increased in number across the luminal surface. Future clinical studies might contribute clinically by confirming whether AS versus VS puncture results in different infection rates.

Fine structural aspects on the web glue production in the golden orb-web spider Trichonephila clavata

ABSTRACT The water-soluble glue substance of the capture threads in Trichonephila clavata is solely produced from two pairs of aggregate silk glands. During the web glue production, secretory vesicles were synthesized via the extensive rough endoplasmic reticulum of epithelial cells. Unlike the clearly described fibrous web production in spiders, the process of aqueous web glue production appears to involve either a condensing or a packaging step by the Golgi complex. In particular, the fine structure of secretory vesicles varies from cell to cell and may represent the secretory cycle. The electron-dense multivesicular bodies were clearly visible as discrete droplets, and the mature secretory product in the glandular epithelium appeared as a spherical vacuole grown by fusion with surrounding small vesicles. Our fine structural observation reveals that the secretion occurs when the release of secreted material involves the loss of part of the cytoplasm. The bleb along the luminal surface of the secretory cells and membrane-bound extracellular vesicles which pinched off from the cell suggests that the secretory product is released by the mechanism of apocrine secretion.

Characteristics and Pattern of Calcified Nodule and/or Nodular Calcification Detected by Intravascular Ultrasound on the Device-Oriented Composite Endpoint (DoCE) in Patients with Heavily Calcified Lesions Who Underwent Rotational Atherectomy-Assisted Percutaneous Coronary Intervention.

This study aimed to determine characteristics and pattern of a calcified nodule (CN) and/or nodular calcification (NC) detected by intravascular ultrasound (IVUS) on the device-oriented composite endpoint (DoCE) in patients with calcified lesions who underwent rotational atherectomy (RA)-assisted percutaneous coronary intervention (PCI). The characteristics and pattern of a CN and/or NC on clinical outcome remain unknown. We retrospectively enrolled patients who underwent RA-assisted PCI at Siriraj Hospital during August 2016 to April 2020. Preprocedural IVUS imaging was mandatory. CN/NC was defined as convex shape of luminal surface and luminal side of calcium with protrusion into the coronary artery lumen as assessed by IVUS. The primary outcome was cumulative of DoCE, defined as the composite of cardiovascular death, myocardial infarction, and clinically-driven target lesion revascularization. Two hundred patients were included. Primary outcome occurred in 14%. The cumulative DoCE was significantly higher in the CN/NC group than that in the non-CN/NC group (20.7% vs. 8.8%, p = 0.022). CN/NC (p = 0.023) and MSA ≤ 5.5 mm2 (p = 0.047) were correlated with a significantly higher cumulative DoCE. CN/NC was the independent predictor for the cumulative DoCE (HR = 2.96, 95% CI 1.08-8.11, p = 0.035). Pattern and characteristic of CN/NC have a prognostic value. Patients with an eccentric CN/NC had a significantly higher cumulative DoCE compared to those CN/NC with concentric calcification (p = 0.014). The presence of a CN/NC in patients with heavily calcified lesions who underwent RA-assisted PCI was found to be associated with increased cumulative 5 year DoCE, especially in patients with an eccentric CN/NC. The clinical trial is registered with TCTR20210616001.