Multiscale Porous Poly (Ether-Ether-Ketone) Structures Manufactured by Powder Bed Fusion Process.

The aim of the study is to create a multiscale highly porous poly (ether-ether-ketone) (PEEK) structure while maintaining mechanical performance; the distribution of pores being generated by the manufacturing process combined with a porogen leaching operation. Salt at 70 wt% concentration was used as a porogen in a dry blend with PEEK powder sintered in the powder bed fusion process. The printed porous PEEK structures were examined and evaluated by scanning electron microscopy, microcomputed tomography, and mechanical testing. The PEEK structures incorporating 70 wt% salt achieved 79-86% porosity, a compressive yield strength of 4.1 MPa, and a yield strain of ∼60%. Due to the salt leaching process, the PEEK porous frameworks were fabricated without the need to drastically reduce the process parameters (defined by the energy density [ED]), hence maintaining the structural integrity and good mechanical performance. The compression results highlighted that the performance is influenced by the printing orientation, level of the PEEK particle coalescence (controlled here by the ED), pore/cell wall thickness, and subsequently, the overall porosity framework. The porous printed PEEK structures could find potential uses in a wide range of applications from tissue engineering, filtration and separation to catalysts, drug release, and gas storage.

Powder Bed Fusion Versus Material Extrusion: A Comparative Case Study on Polyether-Ether-Ketone Cranial Implants.

As the choice of additive manufacturing (AM) technologies is becoming wider with reliable processes and a wider range of materials, the selection of the right technology to fabricate a certain product is becoming increasingly difficult from a technical and cost perspective. In this study polyether-ether-ketone cranial implants were manufactured by two AM techniques: powder bed fusion (PBF) and fused filament fabrication (FFF) and their dimensional accuracy, compression performance, and drop tower impact behavior were evaluated and compared. The results showed that both types of specimens differed from the original computer-aided design; although the origin of the deviation was different, the PBF samples were slightly inaccurate owing to the printing process where the accuracy of the FFF samples was influenced by postprocessing and removal of the scaffolds. The cranial implants fabricated using the FFF method absorbed more energy during the compression and impact tests in comparison with the PBF process. The failure mechanisms revealed that FFF samples have a higher ability to deform and a more consistent failure mechanisms, with the damage localized around the puncture head region. The brittle nature of the PBF samples, a feature observed with other polymers as well, led to complete failure of the cranial implants into several pieces.

Targeted ablation of signal transducer and activator of transduction 1 alleviates inflammation by microglia/macrophages and promotes long-term recovery after ischemic stroke.

BACKGROUND: Brain microglia and macrophages (Mi/MΦ) can shift to a harmful or advantageous phenotype following an ischemic stroke. Identification of key molecules that regulate the transformation of resting Mi/MΦ could aid in the development of innovative therapies for ischemic stroke. The transcription factor signal transducer and activator of transduction 1 (STAT1) has been found to contribute to acute neuronal death (in the first 24 h) following ischemic stroke, but its effects on Mi/MΦ and influence on long-term stroke outcomes have yet to be determined. METHODS: We generated mice with tamoxifen-induced, Mi/MΦ-specific knockout (mKO) of STAT1 driven by Cx3cr1CreER. Expression of STAT1 was examined in the brain by flow cytometry and RNA sequencing after ischemic stroke induced by transient middle cerebral artery occlusion (MCAO). The impact of STAT1 mKO on neuronal cell death, Mi/MΦ phenotype, and brain inflammation profiles were examined 3-5 days after MCAO. Neurological deficits and the integrity of gray and white matter were assessed for 5 weeks after MCAO by various neurobehavioral tests and immunohistochemistry. RESULTS: STAT1 was activated in Mi/MΦ at the subacute stage (3 days) after MCAO. Selective deletion of STAT1 in Mi/MΦ did not alter neuronal cell death or infarct size at 24 h after MCAO, but attenuated Mi/MΦ release of high mobility group box 1 and increased arginase 1-producing Mi/MΦ 3d after MCAO, suggesting boosted inflammation-resolving responses of Mi/MΦ. As a result, STAT1 mKO mice had mitigated brain inflammation at the subacute stage after MCAO and less white matter injury in the long term. Importantly, STAT1 mKO was sufficient to improve functional recovery for at least 5 weeks after MCAO in both male and female mice. CONCLUSIONS: Mi/MΦ-targeted STAT1 KO does not provide immediate neuroprotection but augments inflammation-resolving actions of Mi/MΦ, thereby facilitating long-term functional recovery after stroke. STAT1 is, therefore, a promising therapeutic target to harness beneficial Mi/MΦ responses and improve long-term outcomes after ischemic stroke.

Neuroprotective Effects of TRPM7 Deletion in Parvalbumin GABAergic vs. Glutamatergic Neurons following Ischemia.

Oxidative stress induced by brain ischemia upregulates transient receptor potential melastatin-like-7 (TRPM7) expression and currents, which could contribute to neurotoxicity and cell death. Accordingly, suppression of TRPM7 reduces neuronal death, tissue damage and motor deficits. However, the neuroprotective effects of TRPM7 suppression in different cell types have not been investigated. Here, we found that induction of ischemia resulted in loss of parvalbumin (PV) gamma-aminobutyric acid (GABAergic) neurons more than Ca2+/calmodulin-kinase II (CaMKII) glutamatergic neurons in the mouse cortex. Furthermore, brain ischemia increased TRPM7 expression in PV neurons more than that in CaMKII neurons. We generated two lines of conditional knockout mice of TRPM7 in GABAergic PV neurons (PV-TRPM7-/-) and in glutamatergic neurons (CaMKII-TRPM7-/-). Following exposure to brain ischemia, we found that deleting TRPM7 reduced the infarct volume in both lines of transgenic mice. However, the volume in PV-TRPM7-/- mice was more significantly lower than that in the control group. Neuronal survival of both GABAergic and glutamatergic neurons was increased in PV-TRPM7-/- mice; meanwhile, only glutamatergic neurons were protected in CaMKII-TRPM7-/-. At the behavioral level, only PV-TRPM7-/- mice exhibited significant reductions in neurological and motor deficits. Inflammatory mediators such as GFAP, Iba1 and TNF-α were suppressed in PV-TRPM7-/- more than in CaMKII-TRPM7-/-. Mechanistically, p53 and cleaved caspase-3 were reduced in both groups, but the reduction in PV-TRPM7-/- mice was more than that in CaMKII-TRPM7-/- following ischemia. Upstream from these signaling molecules, the Akt anti-oxidative stress signaling was activated only in PV-TRPM7-/- mice. Therefore, deleting TRPM7 in GABAergic PV neurons might have stronger neuroprotective effects against ischemia pathologies than doing so in glutamatergic neurons.

Optimized mouse model of embolic MCAO: From cerebral blood flow to neurological outcomes.

The embolic middle cerebral artery occlusion (eMCAO) model mimics ischemic stroke due to large vessel occlusion in humans and is amenable to thrombolytic therapy with rtPA. However, two major obstacles, the difficulty of the eMCAO surgery and unpredictable occurrence of clot autolysis, had impeded its application in mice. In this study, we modified catheters to produce suitable fibrin-rich embolus and optimized the eMCAO model using cerebral blood flow (CBF) monitored by both laser Doppler flowmetry (LDF) and 2D laser speckle contrast imaging (LSCI) to confirm occlusion of MCA. The results showed that longer embolus resulted in higher mortality. There was a compensatory increase in MCA territory perfusion after eMCAO associated with decreased infarct volume; however, this was only partly dependent on recanalization as clot autolysis was only observed in ∼30% of mice. Cortical CBF monitoring with LSCI showed that the size of peri-core area at 3 h displayed the best correlation with infarct volume that is attributed to compensatory collateral blood flow. The peri-core area best predicted functional outcome after eMCAO. In summary, we developed a reliable eMCAO mouse model that better mimics embolic ischemic stroke in humans, which will increase the potential for successful translation of stroke neuroprotective therapies.

Adiponectin ameliorates hypoperfusive cognitive deficits by boosting a neuroprotective microglial response.

Vascular cognitive impairment and dementia (VaD) is the second most common type of dementia caused by chronic vascular hypoperfusion. Adiponectin, one of the cytokines produced by adipocytes (adipocytokine), plays a role in CNS pathologies, but its specific function in VaD is unknown. Here, transcriptomic analyses on human brain tissues showed downregulation of adipocytokine/PPAR signaling in VaD patients, with prominent upregulation of pro-inflammatory responses. Using the murine asymmetric common carotid artery stenosis (ACAS) model, we discovered that the adiponectin/PPARγ axis is essential in reducing chronic hypoperfusion-induced cognitive deficits via modulation of microglial function. Adiponectin levels in the plasma increased early after VaD induction, but decreased in the cerebrospinal fluid in the late phase of VaD. Adiponectin deficiency worsened hippocampus-dependent cognitive deficits, exacerbated neuroinflammation and microglia/macrophage activation, and amplified neuronal loss, but these behavioral and histological outcomes were rescued by adipoRon, a small molecule agonist of the adiponectin receptors. AdipoRon boosted PPARγ expression and inhibited pro-inflammatory microglial responses in vitro, thereby protecting ischemic neurons in primary microglia-neuron cocultures. Microglia/macrophage-specific knockout of PPARγ abolished the neuroprotective effects of adipoRon. Collectively, these data confirm the importance of adiponectin/PPARγ signaling in maintaining cognitive functions in chronic hypoperfusion-induced dementia, and thus provide novel therapeutic targets for VaD.

Three-dimensional remodeling of functional cerebrovascular architecture and gliovascular unit in leptin receptor-deficient mice.

The cerebrovascular sequelae of diabetes render victims more susceptible to ischemic stroke, vascular cognitive impairment, and Alzheimer's disease. However, limited knowledge exists on the progressive changes in cerebrovascular structure and functional remodeling in type 2 diabetes. To ascertain the impact of diabetes on whole-brain cerebrovascular perfusion, leptin-receptor-deficient mice were transcardially injected with tomato-lectin before sacrifice. The whole brain was clarified by the Fast free-of-acrylamide clearing tissue technique. Functional vascular anatomy of the cerebrum was visualized by light-sheet microscopy, followed by analysis in Imaris software. We observed enhanced neovascularization in adult db/db mice, characterized by increased branch level and loop structures. Microvascular hypoperfusion was initially detected in juvenile db/db mice, suggesting early onset of insufficient microcirculation. Furthermore, gliovascular unit remodeling was verified by loss of pericytes and overactivation of microglia and astrocytes in adult diabetic mice. However, the integrity of the blood-brain barrier (BBB) was fundamentally preserved, as shown by a lack of extravasation of IgG into the brain parenchyma. In summary, we, for the first time, reveal that functional cerebrovascular remodeling occurs as early as four weeks in db/db mice and the deficit in gliovascular coupling may play a role in cerebral hypoperfusion before BBB breakdown in 16-week-old db/db mice.

Inhibition of TGFß-activated kinase 1 promotes inflammation-resolving microglial/macrophage responses and recovery after stroke in ovariectomized female mice.

TGFß-activated kinase 1 (TAK1) is a master regulator that drives multiple cell death and proinflammatory signaling pathways, making it a promising therapeutic target to treat ischemic stroke. However, whether targeting TAK1 could improve stroke outcomes has never been tested in female subjects, hindering its potential translation into clinical use. Here we examined the therapeutic effect of 5Z-7-Oxozeaenol (OZ), a selective TAK1 inhibitor, in ovariectomized female mice after middle cerebral artery occlusion (MCAO). OZ significantly reduced neuronal cell death and axonal injury at the acute stage and mitigated neuroinflammation at the subacute stage after MCAO in ovariectomized female mice. Consistent with RNA sequencing analysis that TAK1 activation contributed to microglia/macrophage-mediated inflammatory responses in the post-stroke brain, inhibition of TAK1 with OZ caused phenotypic shift of microglia/macrophages toward an inflammation-resolving state. Furthermore, microglia/macrophage-specific TAK1 knockout (TAK1 mKO) reproduced OZ's effects, causally confirming the role of TAK1 in determining proinflammatory microglial/macrophage responses in post-stroke females. Post-stroke treatment with OZ for 5 days effectively promoted long-term neurological recovery and the integrity of both gray matter and white matter in female mice. Together, the TAK1 inhibitor OZ elicits long-lasting improvement of stroke outcomes in female mice, at least partially through enhancing beneficial microglial/macrophage responses and inflammation resolution. Given its therapeutic efficacy on both male and female rodents, TAK1 inhibitor is worth further investigation as a valid treatment to ischemic stroke.

Web Search Trends of Implementing the Patient Autonomy Act in Taiwan.

BACKGROUND: The Patient Autonomy Act was implemented in Taiwan on 6 January 2019. It is the first patient-oriented act in Taiwan, and also the first special act to completely protect patient autonomy in Asia. Our study aimed to investigate the web resources citizens were able to access on the eve of the implementation of the Patient Autonomy Act in Taiwan. METHODS: Patient Autonomy Act-related web resources were searched for by entering 10 related terms individually into the Google search engine in January 2019 and again in April 2019. Search activity data were analyzed using Google Trends. RESULTS: "Advance care planning" and "advance decision" were the most relevant keywords for finding information about the Patient Autonomy Act on the eve of the act's implementation in Taiwan. The main online information sources were non-governmental websites including news sites and online magazines. The related search volume only increased on the eve of implementation. CONCLUSIONS: Even though the Patient Autonomy Act was first published three years before its implementation, the related search volume only increased on the eve of its implementation. Therefore, whether the three-year buffer between its publication and implementation was necessary requires further investigation.

In the Name of Family Medicine: A Nationwide Survey of Registered Names of Family Medicine Clinics in Taiwan.

Family medicine is officially a specialty, but is often not regarded as a specialty by the general public. Past studies have usually investigated the opinions of medical students and resident physicians regarding family medicine, whereas few have focused on practicing family physicians themselves, especially in terms of analyzing how they represent themselves. This study aimed to investigate the patterns of clinic names to better apprehend whether general practitioners see themselves as being on an equal footing with other medical specialists. The registered names, medical specialties, and levels of urbanization of all clinics of Western medicine in Taiwan were collected. For clinics of each specialty, we examined whether their names contained the corresponding specialty designation. For example, a family medicine clinic was checked to determine whether its name contained the term "family medicine" or its abbreviation. The naming of family medicine clinics was then compared with that of clinics with other specialties. Of the 9867 Western medicine clinics included in this study, two-thirds (n = 6592) were single-specialty clinics. In contrast to the high percentages of single-specialty clinics of other specialties with specialty-containing names (97.5% for ophthalmology, 94.8% for dermatology, and 94.7% for otolaryngology), only 13.3% (132/989) of the family medicine clinics had such names. In addition, the urban family medicine clinics had a higher proportion (15.2%, 74/487) of specialty-containing names than the suburban (12.6%, 44/349) and rural family medicine clinics (9.2%, 14/153). Overall, a low percentage of family medicine clinics in Taiwan included "family medicine" in their names. This issue of professional identity deserves further qualitative investigation.

Hospital visiting policies in the time of coronavirus disease 2019: A nationwide website survey in Taiwan.

BACKGROUND: Coronavirus disease 2019 (COVID-19), a novel infectious coronavirus disease, has become a worldwide pandemic. Infection control precautions for hospital visitors are needed to avoid cluster outbreaks, so this study investigated the visiting policies of all the hospitals in Taiwan in the time of COVID-19. METHODS: From March 15, 2020, to March 18, 2020, we searched the official websites of all 472 National Health Insurance-contracted hospitals to determine their visiting policies. For those hospitals that had posted new visiting policies and still allowed visits to ordinary wards, we recorded the relevant details shown on their websites, including the number of visitors allowed at one time, the number of visiting slots per day, the total visiting hours per day, and the rules provided to visitors before visiting. RESULTS: During the study period, 276 (58.5%) hospitals had posted new visiting policies on their websites, with higher proportions of academic medical centers (92.0%, 23/25) and metropolitan hospitals (91.5%, 75/82) than local community hospitals (48.8%, 178/365) doing so. Visits to ordinary wards were forbidden in 83 hospitals among those. Among the 193 hospitals that had new visiting policies and still allowed visits to ordinary wards, 73.1% (n = 141) restricted visitors to two at a time and 54.9% (n = 106) restricted visits to two visiting slots per day. Furthermore, history taking regarding travel, occupation, contacts, and cluster information was mentioned by 82.4% (n = 159) of these 193 hospitals, body temperature monitoring by 78.2% (n = 151), hand hygiene by 63.2% (n = 122), and identity checks by 51.8% (n = 100). CONCLUSION: In the time of COVID-19 covered by this study, about three-fifths of the hospitals in Taiwan had posted their visiting policies for ordinary wards on their websites. Furthermore, the thoroughness with which such visiting policies have been enforced also requires investigation.

Visiting Policies of Hospice Wards during the COVID-19 Pandemic: An Environmental Scan in Taiwan.

During an epidemic, almost all healthcare facilities restrict the visiting of patients to prevent disease transmission. For hospices with terminally ill patients, the trade-off between compassion and infection control becomes a difficult decision. This study aimed to survey the changes in visiting policy for all 76 hospice wards in Taiwan during the COVID-19 pandemic in March 2020. The altered visiting policies were assessed by the number of visitors per patient allowed at one time, the daily number of visiting slots, the number of hours open daily, and requisites for hospice ward entry. The differences in visiting policies between hospice wards and ordinary wards were also investigated. Data were collected by reviewing the official website of each hospital and were supplemented by phone calls in cases where no information was posted on the website. One quarter (n = 20) of hospice wards had different visiting policies to those of ordinary wards in the same hospital. Only one hospice ward operated an open policy, and in contrast, nine (11.8%) stopped visits entirely. Among the 67 hospice wards that allowed visiting, at most, two visitors at one time per patient were allowed in 46 (68.6%), one visiting time daily was allowed in 32 (47.8%), one hour of visiting per day was allowed in 29 (43.3%), and checking of identity and travel history was carried out in 12 wards (17.9%). During the COVID-19 pandemic, nearly all hospice wards in Taiwan changed their visiting policies, but the degree of restriction varied. Further studies could measure the impacts of visiting policy changes on patients and healthcare professionals.

Transforming Growth Factor Beta-Activated Kinase 1-Dependent Microglial and Macrophage Responses Aggravate Long-Term Outcomes After Ischemic Stroke.

Background and Purpose- Microglia/macrophages (Mi/MΦ) can profoundly influence stroke outcomes by acquiring functionally dominant phenotypes (proinflammatory or anti-inflammatory; deleterious or salutary). Identification of the molecular mechanisms that dictate the functional status of Mi/MΦ after brain ischemia/reperfusion may reveal novel therapeutic targets for stroke. We hypothesized that activation of TAK1 (transforming growth factor beta-activated kinase 1), a key MAP3K upstream of multiple inflammation-regulating pathways, drives Mi/MΦ toward a proinflammatory phenotype and potentiates ischemia/reperfusion brain injury. Methods- Young adult mice were subjected to 1 hour of middle cerebral artery occlusion (MCAO) followed by reperfusion. TAK1 was targeted by tamoxifen-induced Mi/MΦ-specific knockout or administration of a selective inhibitor 5Z-7-Oxozeaenol after MCAO. Neurobehavioral deficits and long-term gray matter and white matter injury were assessed up to 35 days after MCAO. Mi/MΦ functional status and brain inflammatory profiles were assessed 3 days after MCAO by RNA-seq, flow cytometry, and immunohistochemistry. Results- TAK1 Mi/MΦ-specific knockout markedly ameliorated neurological deficits in the rotarod and cylinder tests for at least 35 days after MCAO. Mechanistically, RNA-seq of purified brain Mi/MΦ demonstrated that proinflammatory genes and their predicted biological functions were downregulated or inhibited in microglia and macrophages from TAK1 Mi/MΦ-specific knockout mice versus WT mice 3 days after MCAO. Consistent with the anti-inflammatory phenotype of Mi/MΦ-specific knockout, oxozeaenol treatment mitigated neuroinflammation 3 days after MCAO, manifested by less Iba1+/CD16+ proinflammatory Mi/MΦ and suppressed brain invasion of various peripheral immune cells. Oxozeaenol treatment beginning 2 hours after MCAO improved long-term sensorimotor and cognitive functions in the foot fault, rotarod, and water maze tests. Furthermore, Oxozeaenol promoted both gray matter and white matter integrity 35 days after MCAO. Conclusions- TAK1 promotes ischemia/reperfusion-induced inflammation, brain injury, and maladaptive behavior by enhancing proinflammatory and deleterious Mi/MΦ responses. Therefore, TAK1 inhibition is a promising therapy to improve long-term stroke outcomes.

Author Correction: Additive manufacture of complex 3D Au-containing nanocomposites by simultaneous two-photon polymerisation and photoreduction.

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Additive manufacture of complex 3D Au-containing nanocomposites by simultaneous two-photon polymerisation and photoreduction.

The fabrication of complex three-dimensional gold-containing nanocomposite structures by simultaneous two-photon polymerisation and photoreduction is demonstrated. Increased salt delivers reduced feature sizes down to line widths as small as 78 nm, a level of structural intricacy that represents a significant advance in fabrication complexity. The development of a general methodology to efficiently mix pentaerythritol triacrylate (PETA) with gold chloride hydrate (HAuCl4∙3H2O) is reported, where the gold salt concentration is adjustable on demand from zero to 20 wt%. For the first-time 7-Diethylamino-3-thenoylcoumarin (DETC) is used as the photoinitiator. Only 0.5 wt% of DETC was required to promote both polymerisation and photoreduction of up to 20 wt% of gold salt. This efficiency is the highest reported for Au-containing composite fabrication by two-photon lithography. Transmission Electron Microscopy (TEM) analysis confirmed the presence of small metallic nanoparticles (5.4 ± 1.4 nm for long axis / 3.7 ± 0.9 nm for short axis) embedded within the polymer matrix, whilst X-ray Photoelectron Spectroscopy (XPS) confirmed that they exist in the zero valent oxidation state. UV-vis spectroscopy defined that they exhibit the property of localised surface plasmon resonance (LSPR). The capability demonstrated in this study opens up new avenues for a range of applications, including plasmonics, metamaterials, flexible electronics and biosensors.

Fast free-of-acrylamide clearing tissue (FACT)-an optimized new protocol for rapid, high-resolution imaging of three-dimensional brain tissue.

Fast Free-of-Acrylamide Clearing Tissue (FACT) is a new sodium dodecyl sulfate (SDS)-based clearing protocol for the chemical clearing and imaging of brain tissue containing transgenic or immunolabeled fluorescent proteins. In the present study, we have developed this new method and optimized multiple dimensions of the workflow, including reduced clearing time, improved efficiency of fluorescent signals without the need for electrophoretic or complex instrumentations, preservation of cytoarchitectural details, optimized confocal microscopy, and accelerated data collection. We systematically compared seven clearing protocols with the FACT protocol, using transgenic mouse brains with fluorochrome expression in microglia. Only six days were required for detecting transgene-labeled markers in a 1-mm thick brain slice from adult mice, and 14 days were required for detecting antibody-labeled markers in the same-sized tissue. Preservation of fluorescent signal was achieved by decreasing clearing time, adjusting the pH of the SDS solution, and using the appropriate temperature for tissue clearing, all of which contributed to the superiority of our method. We conclude that the FACT protocol can be successfully applied to the fluorescent imaging of mouse brain tissue, and will facilitate structural analyses and connectomics of large assemblies of cells and their networks in the context of three-dimensional organ systems.

Additive Manufacture of Three Dimensional Nanocomposite Based Objects through Multiphoton Fabrication.

Three-dimensional structures prepared from a gold-polymer composite formulation have been fabricated using multiphoton lithography. In this process, gold nanoparticles were simultaneously formed through photoreduction whilst polymerisation of two possible monomers was promoted. The monomers, trimethylopropane triacrylate (TMPTA) and pentaerythritol triacrylate (PETA) were mixed with a gold salt, but it was found that the addition of a ruthenium(II) complex enhanced both the geometrical uniformity and integrity of the polymerised/reduced material, enabling the first production of 3D gold-polymer structures by single step multiphoton lithography.

Ultrastructural identification of telocytes in the muscularis of chicken ileum.

Telocytes (TCs) are a specialized type of interstitial cells, characterized by a small cell body and long, thin processes, that have recently been identified in various cavitary and non-cavitary organs of humans and laboratory mammals. Chickens present significant economical and scientific notability; however, ultrastructural identification of TCs remains unclear in birds. The aim of the present study was to describe electron microscopic evidence for the presence of TCs in the chicken gut. The ileum of healthy adult broiler chickens (n=10) was studied by transmission electron microscopy. TCs are characterized by several, long (tens to hundreds of µm) prolongations called telopodes (Tps). Tps, which are below the resolving power of light microscopy, display podomeres (thin segments of ≤0.2 µm) and podoms (dilations accommodating caveolae, mitochondria and endoplasmic reticulum). TCs were observed in every field, but were predominantly located in the myenteric plexus and the lamina propria. Tps frequently establish close spatial relationships with immune cells, blood vessels and nerve endings. On the basis of their distribution and morphology, it was hypothesized that the different locations of TCs may be associated with different roles.