Long-term supplementation with anthocyanin-rich or -poor Rubus idaeus berries does not influence microvascular architecture nor cognitive outcome in the APP/PS-1 mouse model of Alzheimer's disease.

Disruption of microvascular architecture is a common pathogenic mechanism in the progression of Alzheimer's disease (AD). Given the anti-angiogenic activity of berry (poly)phenols, we investigated whether long-term feeding of Rubus idaeus (raspberries) could ameliorate cerebral microvascular pathology and improve cognition in the APP/PS-1 mouse model of AD. Male C57Bl/6J mice (50 wild type, 50 APP/PS-1) aged 4-months were fed for 24-weeks, with a normal diet enriched with either 100 mg/day glucose (control diet) or supplemented with glucose and freeze-dried anthocyanin-rich (red) or -poor (yellow) raspberries (100 mg/day) and assessed/sampled post intervention. Cerebral microvascular architecture of wild-type mice was characterised by regularly spaced capillaries with uniform diameters, unlike APP/PS-1 transgenic mice which showed dysregulated microvascular architecture. Long-term feeding of raspberries demonstrated limited modulation of microbiota and no substantive effect on microvascular architecture or cognition in either mice model although changes were evident in endogenous cerebral and plasmatic metabolites.

Microbial sophorolipids inhibit colorectal tumour cell growth in vitro and restore haematocrit in Apcmin+/- mice.

Sophorolipids are glycolipid biosurfactants consisting of a carbohydrate sophorose head with a fatty acid tail and exist in either an acidic or lactonic form. Sophorolipids are gaining interest as potential cancer chemotherapeutics due to their inhibitory effects on a range of tumour cell lines. Currently, most anti-cancer studies reporting the effects of sophorolipids have focused on lactonic preparations with the effects of acidic sophorolipids yet to be elucidated. We produced a 94% pure acidic sophorolipid preparation which proved to be non-toxic to normal human colonic and lung cells. In contrast, we observed a dose-dependent reduction in viability of colorectal cancer lines treated with the same preparation. Acidic sophorolipids induced apoptosis and necrosis, reduced migration, and inhibited colony formation in all cancer cell lines tested. Furthermore, oral administration of 50 mg kg-1 acidic sophorolipids over 70 days to Apcmin+/- mice was well tolerated and resulted in an increased haematocrit, as well as reducing splenic size and red pulp area. Oral feeding did not affect tumour numbers or sizes in this model. This is the first study to show that acidic sophorolipids dose-dependently and specifically reduces colon cancer cell viability in addition to reducing tumour-associated bleeding in the Apcmin+/- mouse model. KEY POINTS: • Acidic sophorolipids are produced by yeast species such as Starmerella bombicola. • Acidic sophorolipids selectively killed colorectal cells with no effect on healthy gut epithelia. • Acidic sophorolipids reduced tumour-associated gut bleed in a colorectal mouse model.

Microvascular ultrastructural changes precede cognitive impairment in the murine APPswe/PS1dE9 model of Alzheimer's disease.

Cerebral and systemic organ microvascular pathologies coexist with human Alzheimer's disease (AD) neuropathology. In this study, we hypothesised that both cerebral and systemic microvascular pathologies exist in 4- to 5-month-old male APPswe/PS1dE9 (APP/PS1) transgenic mice prior to the onset of cognitive impairment. To assess this we examined recognition memory in both wild-type and APP/PS1 mice using the object recognition task (ORT; n = 11 per group) and counted thioflavin-S-positive plaques in brain (n = 6 per group). Vascular casts of brain, liver, spleen and kidneys were examined using scanning electron microscopy (n = 6 per group), and the urinary albumin-to-creatinine ratio (uACR; n = 5 per group) was measured as an index of glomerular permeability. Murine recognition memory was intact, as demonstrated by a significant preference for the novel object in the ORT paradigm. Brain sections of wild-type mice were devoid of thioflavin-S positivity, whereas age-matched APP/PS1 mice had an average of 0.88 ± 0.22 thioflavin-S-positive plaques in the cortex, 0.42 ± 0.17 plaques in the dentate gyrus and 0.30 ± 0.07 plaques in the cornus ammonis 1 region. The profiles of casted cerebral capillaries of wild-type mice were smooth and regular in contrast to those of APP/PS1 mice which demonstrate characteristic (0.5-4.6 µm) 'tags'. APP/PS1 mice also had a significantly reduced hepatic vessel number (p = 0.0002) and an increase in the number of splenic microvascular pillars (p = 0.0231), in the absence of changes in either splenic microvascular density (p = 0.3746) or glomerular ultrastructure. The highly significant reduction in uACR in APP/PS1 mice compared to wild-type (p = 0.0079) is consistent with glomerular microvascular dysfunction. These findings highlight early microvascular pathologies in 4- to 5-month-old APP/PS1 transgenic mice and may indicate an amenable target for pharmacological intervention in AD.

Adjuvant Antibiotic Activity of Acidic Sophorolipids with Potential for Facilitating Wound Healing.

The sophorolipid class of biosurfactants is finding increasing use in personal care as well as pharmaceutical products and has the potential to disrupt biofilm formation and inhibit the growth of a variety of clinically relevant organisms. In order to investigate potential biomedical applications of sophorolipids derived from nonpathogenic organisms, we fractionated and purified glycolipid biosurfactant sophorolipids produced by the yeast Starmerella bombicola, which yielded nonacetylated acidic C18:1 congeners that were essentially free from other contaminants (>95% purity). These acidic sophorolipids have antimicrobial activities against the nosocomial infective agents Enterococcus faecalis and Pseudomonas aeruginosa, with significant reductions in CFU at concentrations of as low as 5 mg ml-1 In addition, the sophorolipid showed similar effects against the same two bacterial strains when combined with kanamycin or cefotaxime. As a potential use of these sophorolipids is as a component of topically applied creams for the treatment of wound infections, it is clear that they must have no demonstrable adverse effect on wound healing. To assess this, we evaluated mammalian cell toxicity in vitro using viability tests, which revealed no adverse effect on either endothelial or keratinocyte-derived cell lines with sophorolipid concentrations of < 0.5 mg ml-1 In addition, in vivo experiments using a mouse skin wounding assay revealed that the time course of healing wounds was unaffected by the application of sophorolipid-containing creams, and histological examination of regenerated skin tissue confirmed that the healing process was similar to that observed for control animals, with no evidence of inflammation. These results are consistent with the suggestion that acidic sophorolipids can be used as a component of antimicrobial creams to reduce the risk of wound infection during healing.

MALDI MSI analysis of lipid changes in living skin equivalents in response to emollient creams containing palmitoylethanolamide.

Mass spectrometry imaging (MSI) is a powerful tool for the study of intact tissue sections. The use of matrix-assisted laser desorption/ionisation (MALDI) MSI for the study of the distribution and effect of emollient treatment on sections of reconstructed living skin equivalents during their development and maturation is described. Living skin equivalent (LSE) samples were obtained at 14days development, re-suspended in maintenance medium and incubated for 24h after delivery. The medium was changed, the LSE treated with either Physiogel A.I.® or Oilatum Junior® emollients and then re-incubated and samples taken at 4, 6 and 24h time points. Mass spectra and mass spectral images were recorded from 12µm sections of the LSE taken at each time point for comparison using MALDI mass spectrometry (MS). It was possible to detect ions characteristic of each emollient in the LSE. In addition a number of lipid species previously reported as being significant in the maturation of the LSE were observable. At the 24h time point, the images revealed what appeared to be differences in the organisation of the skin cells observed across the Physiogel A.I.® treatment group tissue sections when directly compared to the untreated tissue group.

A correlative imaging based methodology for accurate quantitative assessment of bone formation in additive manufactured implants.

A correlative imaging methodology was developed to accurately quantify bone formation in the complex lattice structure of additive manufactured implants. Micro computed tomography (µCT) and histomorphometry were combined, integrating the best features from both, while demonstrating the limitations of each imaging modality. This semi-automatic methodology registered each modality using a coarse graining technique to speed the registration of 2D histology sections to high resolution 3D µCT datasets. Once registered, histomorphometric qualitative and quantitative bone descriptors were directly correlated to 3D quantitative bone descriptors, such as bone ingrowth and bone contact. The correlative imaging allowed the significant volumetric shrinkage of histology sections to be quantified for the first time (~15 %). This technique demonstrated the importance of location of the histological section, demonstrating that up to a 30 % offset can be introduced. The results were used to quantitatively demonstrate the effectiveness of 3D printed titanium lattice implants.

Restoration of cerebral and systemic microvascular architecture in APP/PS1 transgenic mice following treatment with Liraglutide™.

OBJECTIVE: Cerebral microvascular impairments occurring in AD may reduce Aß peptide clearance and impact upon circulatory ultrastructure and function. We hypothesized that microvascular pathologies occur in organs responsible for systemic Aß peptide clearance in a model of AD and that Liraglutide (Victoza(®)) improves vessel architecture. METHODS: Seven-month-old APP/PS1 and age-matched wild-type mice received once-daily intraperitoneal injections of either Liraglutide or saline (n = 4 per group) for eight weeks. Casts of cerebral, splenic, hepatic, and renal microanatomy were analyzed using SEM. RESULTS: Casts from wild-type mice showed regularly spaced microvasculature with smooth lumenal profiles, whereas APP/PS1 mice revealed evidence of microangiopathies including cerebral microanuerysms, intracerebral microvascular leakage, extravasation from renal glomerular microvessels, and significant reductions in both splenic sinus density (p = 0.0286) and intussusceptive microvascular pillars (p = 0.0412). Quantification of hepatic vascular ultrastructure in APP/PS1 mice revealed that vessel parameters (width, length, branching points, intussusceptive pillars and microaneurysms) were not significantly different from wild-type mice. Systemic administration of Liraglutide reduced the incidence of cerebral microanuerysms and leakage, restored renal microvascular architecture and significantly increased both splenic venous sinus number (p = 0.0286) and intussusceptive pillar formation (p = 0.0129). CONCLUSION: Liraglutide restores cerebral, splenic, and renal architecture in APP/PS1 mice.

Lipid changes within the epidermis of living skin equivalents observed across a time-course by MALDI-MS imaging and profiling.

BACKGROUND: Mass spectrometry imaging (MSI) is a powerful tool for the study of intact tissue sections. Here, its application to the study of the distribution of lipids in sections of reconstructed living skin equivalents during their development and maturation is described. METHODS: Living skin equivalent (LSE) samples were obtained at 14 days development, re-suspended in maintenance medium and incubated for 24 h after delivery. The medium was then changed, the LSE re-incubated and samples taken at 4, 6 and 24 h time points. Mass spectra and mass spectral images were recorded from 12 µm sections of the LSE taken at each time point for comparison using matrix assisted laser desorption ionisation mass spectrometry. RESULTS: A large number of lipid species were identified in the LSE via accurate mass-measurement MS and MSMS experiments carried out directly on the tissue sections. MS images acquired at a spatial resolution of 50 µm × 50 µm showed the distribution of identified lipids within the developing LSE and changes in their distribution with time. In particular development of an epidermal layer was observable as a compaction of the distribution of phosphatidylcholine species. CONCLUSIONS: MSI can be used to study changes in lipid composition in LSE. Determination of the changes in lipid distribution during the maturation of the LSE will assist in the identification of treatment responses in future investigations.

Androgen deprivation results in time-dependent hypoxia in LNCaP prostate tumours: informed scheduling of the bioreductive drug AQ4N improves treatment response.

Androgen withdrawal induces hypoxia in androgen-sensitive tissue; this is important as in the tumour microenvironment, hypoxia is known to drive malignant progression. Our study examined the time-dependent effect of androgen deprivation therapy (ADT) on tumour oxygenation and investigated the role of ADT-induced hypoxia on malignant progression in prostate tumours. LNCaP xenografted tumours were treated with anti-androgens and tumour oxygenation measured. Dorsal skin fold (DSF) chambers were used to image tumour vasculature in vivo. Quantitative PCR (QPCR) identified differential gene expression following treatment with bicalutamide. Bicalutamide-treated and vehicle-only-treated tumours were re-established in vitro, and invasion and sensitivity to docetaxel were measured. Tumour growth delay was calculated following treatment with bicalutamide combined with the bioreductive drug AQ4N. Tumour oxygenation measurements showed a precipitate decrease following initiation of ADT. A clinically relevant dose of bicalutamide (2 mg/kg/day) decreased tumour oxygenation by 45% within 24 hr, reaching a nadir of 0.09% oxygen (0.67 ± 0.06 mmHg) by Day 7; this persisted until Day 14 when it increased up to Day 28. Using DSF chambers, LNCaP tumours treated with bicalutamide showed loss of small vessels at Days 7 and 14 with revascularisation occurring by Day 21. QPCR showed changes in gene expression consistent with the vascular changes and malignant progression. Cells from bicalutamide-treated tumours were more malignant than vehicle-treated controls. Combining bicalutamide with AQ4N (50 mg/kg, single dose) caused greater tumour growth delay than bicalutamide alone. Our study shows that bicalutamide-induced hypoxia selects for cells that show malignant progression; targeting hypoxic cells may provide greater clinical benefit.

Mitigating SARS-CoV-2 in the Deployed Environment.

INTRODUCTION: Unlike other communal living environments (universities, boarding schools, and camps) that have been suspended during the COVID-19 pandemic, the deployed military force must continue its mission. Early challenges in the 2020 deployed environment included limited availability of living and quarantine space and limited testing capacity. This is a brief report of stringent quarantine strategies employed to newly arriving cohorts at a NATO and U.S. military base to prevent release of SARS-CoV-2 into a larger base population. METHODS: With awareness of the worldwide pandemic, beginning in late February 2020, all personnel arriving to the Hamid Karzai International Airport NATO base were quarantined for 14 days to prevent interaction with the wider base population. Testing capacity was limited. Names, locations, and dates of those within quarantine were tracked to improve contact tracing. Between February and April 2020, the first cases of SARS-CoV-2 were diagnosed on a military base in Afghanistan within quarantine. RESULTS: Within quarantine, 11 males became PCR positive for SARS-CoV-2 during April 2020. Five of the 11 were PCR tested for symptoms of fever, cough, or loss of taste. A sixth individual, who had been asymptomatic upon leaving the base after completion of quarantine, later developed symptoms and tested positive. Another five asymptomatic individuals were found with antibody testing just before planned release from 14 days of quarantine post-exposure and confirmed with PCR testing. All PCR-positive individuals were diagnosed before being released into the general population of the base because of strict screening, quarantine, and exit criteria. CONCLUSION: Quarantine creates significant strain on resources in a deployed environment. Group quarantine facilities where social distancing is limited allow for the possibility for intra-quarantine transmission of SARS-CoV-2. Ideally, PCR testing is done upon entry into quarantine and upon exit. With the possibility of false-negative PCR or limited PCR testing, we recommend daily symptom screening, pulse oximetry, temperature checks, and small quarantine groups that must "graduate" together-all meeting exit criteria. Any introduction of new individual, even with negative testing, to a group increases risk of SARS-CoV-2 transmission.Upon exit of quarantine, testing should be performed, regardless of entry testing. If PCR is limited, serology testing should be done, followed by PCR, if positive. Serology testing can be combined with clinical judgment to conserve PCR testing for quarantine release of asymptomatic individuals.

Temporal changes in microvessel leakiness during wound healing discriminated by in vivo fluorescence recovery after photobleaching.

Regeneration of injured tissue is a dynamic process, critically dependent on the formation of new blood vessels and restructuring of the nascent plexus. Endothelial barrier function, a functional correlate of vascular restructuring and maturation, was quantified via intravital microscopic analysis of 150 kDa FITC-dextran-perfused blood vessels within discrete wounds created in the panniculus carnosus (PC) muscle of dorsal skinfold chamber (DSC) preparations in mice. Time to recovery of half-peak fluorescence intensity (t(1/2)) within individual vessel segments in three functional regions of the wound (pre-existing vessels, angiogenic plexus and blind-ended vessels (BEVs)) was quantified using in vivo fluorescence recovery after photobleaching (FRAP) and linear regression analysis of recovery profiles. Plasma flux across the walls of new vessel segments, particularly BEVs, was greater than that of pre-existing vessels at days 5-7 after injury (P < 0.05). TNP-470 reduced the permeability of BEVs at the leading edge of the advancing vascular plexus as measured by the decrease in luminal t(1/2) (P < 0.05), confirming the utility of FRAP as a quantitative measure of endothelial barrier function. Furthermore, these data are suggestive of a role for TNP-470 in selection for less leaky vascular segments within healing wounds. Increased FITC-dextran leakage was observed from pre-existing vessels after treatment with TNP-470 (P < 0.05), consistent with induction of transient vascular damage, although the significance of this finding is unclear. Using in vivo FRAP this study demonstrates the relationship between temporal changes in microvascular macromolecular flux and the morphology of maturing vascular segments. This combination of techniques may be useful to assess the therapeutic potential of angiogenic agents in restoring pre-injury levels of endothelial barrier function, following the establishment of a functional vascular plexus such as in models of wounding or tumour development.

Dynamics of angiogenesis during wound healing: a coupled in vivo and in silico study.

OBJECTIVE: The most critical determinant of restoration of tissue structure during wound healing is the re-establishment of a functional vasculature, which largely occurs via angiogenesis, specifically endothelial sprouting from the pre-existing vasculature. MATERIALS AND METHODS: We used confocal microscopy to capture sequential images of perfused vascular segments within the injured panniculus carnosus muscle in the mouse dorsal skin-fold window chamber to quantify a range of microcirculatory parameters during the first nine days of healing. This data was used to inform a mathematical model of sequential growth of the vascular plexus. The modeling framework mirrored the experimental circular wound domain and incorporated capillary sprouting and endothelial cell (EC) sensing of vascular endothelial growth factor gradients. RESULTS: Wound areas, vessel densities and vessel junction densities obtained from the corresponding virtual wound were in excellent agreement both temporally and spatially with data measured during the in vivo healing process. Moreover, by perturbing the proliferative ability of ECs in the mathematical model, this leads to a severe reduction in vascular growth and poor healing. Quantitative measures from this second set of simulations were found to correlate extremely well with experimental data obtained from animals treated with an agent that targets endothelial proliferation (TNP-470). CONCLUSION: Our direct combination and comparison of in vivo longitudinal analysis (over time in the same animal) and mathematical modeling employed in this study establishes a useful new paradigm. The virtual wound created in this study can be used to investigate a wide range of experimental hypotheses associated with wound healing, including disorders characterized by aberrant angiogenesis (e.g., diabetic models) and the effects of vascular enhancing/disrupting agents or therapeutic interventions such as hyperbaric oxygen.

Thrombophilic-type placental pathologies and skeletal growth delay following maternal administration of angiostatin4.5 in mice.

During placentation, the concentration of fibrinous deposits on the surfaces of maternal vasculature plays a role in villous development and has been strongly implicated in the pathophysiology of human fetal growth restriction (FGR). Fibrinous deposits are conspicuous sites of platelet aggregation where there is local activation of the hemostatic cascade. During activation of the hemostatic cascade, a number of pro- and antiangiogenic agents may be generated at the cell surface, and an imbalance in these factors may contribute to the placental pathology characteristic of FGR. We tested the hypothesis that angiostatin(4.5) (AS(4.5)), a cleavage fragment of plasminogen liberated at the cell surface, is capable of causing FGR in mice. Increased maternal levels of AS(4.5) in vivo result in reproducible placental pathology, including an altered vascular compartment (both in decidual and labyrinthine layers) and increased apoptosis throughout the placenta. In addition, there is significant skeletal growth delay and conspicuous edema in fetuses from mothers that received AS(4.5). Maternally generated AS(4.5), therefore, can access maternal placental vasculature and have a severe effect on placental architecture and inhibit fetal development in vivo. These findings strongly support the hypothesis that maternal AS(4.5) levels can influence placental development, possibly by directly influencing trophoblast turnover in the placenta, and contribute to fetal growth delay in mice.

Reduction of mechanical loading in tendons induces heterotopic ossification and activation of the ß-catenin signaling pathway.

BACKGROUND: Tendons are the force transferring tissue that enable joint movement. Excessive mechanical loading is commonly considered as a primary factor causing tendinopathy, however, an increasing body of evidence supports the hypothesis that overloading creates microdamage of collagen fibers resulting in a localized decreased loading on the cell population within the damaged site. Heterotopic ossification is a complication of late stage tendinopathy, which can significantly affect the mechanical properties and homeostasis of the tendon. Here, we the examine the effect of mechanical underloading on tendon ossification and investigate its underlying molecular mechanism. METHOD: Rabbit Achilles tendons were dissected and cultured in an underloading environment (3% cyclic tensile stain,0.25 â€‹Hz, 8 â€‹h/day) for either 10, 15 or 20 days. Using isolated tendon-derived stem cells (TDSCs) 3D constructs were generated, cultured and subjected to an underloading environment for 6 days. Histological assessments were performed to evaluate the structure of the 3D constructs; qPCR and immunohistochemistry were employed to study TDSC differentiation and the ß-catenin signal pathway was investigated by Western blotting. Mechanical testing was used to determine ability of the tendon to withstand force generation. RESULT: Tendons cultured for extended times in an environment of underloading showed progressive heterotopic ossification and a reduction in biomechanical strength. qPCR revealed that 3D TDSCs constructs cultured in an underloading environment exhibited increased expression of several osteogenic genes: these include RUNX2, ALP and osteocalcin in comparison to tenogenic differentiation markers (scleraxis and tenomodulin). Immunohistochemical analysis further confirmed high osteocalcin production in 3D TDSCs constructs subject to underloading. Western blotting of TDSC constructs revealed that ß-catenin accumulation and translocation were associated with an increase in phosphorylation at Ser552 and decrease phosphorylation at Ser33. CONCLUSION: These findings unveil a potential mechanism for heterotopic ossification in tendinopathy due to the underloading of TDSCs at the damage sites, and also that ß-catenin could be a potential target for treating heterotopic ossification in tendons. THE TRANSLATIONAL POTENTIAL: Tendon heterotopic ossification detrimentally affect quality of life especially for those who has atheletic career. This study reveals the possible mechanism of heterotpic ossification in tendon related to mechanical loading. This study provided the possible to develop a mechanical stimulation protocol for preventive and therapeutic purpose for tendon heterotopic ossification.

A bio-inductive collagen scaffold that supports human primary tendon-derived cell growth for rotator cuff repair.

BACKGROUND: Rotator Cuff (RC) tendon tearing is a common clinical problem and there is a high incidence of revision surgery due to re-tearing. In an effort to improve patient outcome and reduce surgical revision, scaffolds have been widely used for augmentation of RC repairs. However, little is known about how scaffolds support tendon stem cell growth or facilitate tendon regeneration. The purpose of this study is to evaluate the structural and biological properties of a bioactive collagen scaffold (BCS) with the potential to promote tendon repair. Additionally, we conducted a pilot clinical study to assess the safety and feasibility of using the BCS for repair of RC tears. METHODS: A series of physical, ultrastructural, molecular and in vitro tests determined the biocompatibility and teno-inductive properties of this BCS. In addition, a prospective case study of 18 patients with RC tendon tears (>20 â€‹mm in diameter) was performed in an open-label, single-arm study, involving either mini-open or arthroscopic surgical RC repair with the BCS. Clinical assessment of RC repair status was undertaken by MRI-imaging at baseline, 6 and 12 months and patient evaluated questionnaires were taken at baseline as well as 3, 6 & 12 months. RESULTS: The BCS consists of highly purified type-I collagen, in bundles of varying diameter, arranged in a higher order tri-laminar structure. BCS have minimal immunogenicity, being cell and essentially DNA-free as well as uniformly negative for the porcine α-Gal protein. BCS seeded with human primary tendon-derived cells and exposed to 6% uniaxial loading conditions in vitro, supported increased levels of growth and proliferation as well as up-regulating expression of tenocyte differentiation marker genes including TNMD, Ten-C, Mohawk and Collagen-1α1. To test the safety and feasibility of using the BCS for augmentation of RC repairs, we followed the IDEAL framework and conducted a first, open-label single arm prospective case series study of 18 patients. One patient was withdrawn from the study at 3 months due to wound infection unrelated to the BCS. The remaining 17 cases showed that the BCS is safe to be implanted. The patients reported encouraging improvements in functional outcomes (ASES, OSS and Constant-Murley scores), as well as quality of life assessments (AQoL) and a reduction in VAS pain scores. MRI assessment at 12 months revealed complete healing in 64.8% patients (11/17), 3 partial thickness re-tears (17.6%) and 3 full thickness re-tears (17.6%). CONCLUSION: The BCS is composed of type-I collagen that is free of immunogenic proteins and supports tendon-derived cell growth under mechanical loading in vitro. This pilot study shows that it is safe and feasible to use BCS for RC argumentation and further controlled prospective studies are required to demonstrate its efficacy. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: The results of this study indicate that this bioactive collagen scaffold has unique properties for supporting tendon growth and that it is non-immunogenic. The clinical study further confirms that the scaffold is a promising biological device for augment of human rotator cuff repairs.

Quantitation of microcomputed tomography-imaged ocular microvasculature.

PURPOSE: To quantitatively assess microvascular dimensions in the eyes of neonatal wild-type and VEGF(120)-tg mice, using a novel combination of techniques which permit three-dimensional (3D) image reconstruction. METHODS: A novel combination of techniques was developed for the accurate 3D imaging of the microvasculature and demonstrated on the hyaloid vasculature of the neonatal mouse eye. Vascular corrosion casting is used to create a stable replica of the vascular network and X-ray microcomputed tomography (muCT) to obtain the 3D images. In-house computer-aided image analysis techniques were then used to perform a quantitative morphological analysis of the images. RESULTS: With the use of these methods, differences in the numbers of vessel segments, their diameter, and volume of vessels in the vitreous compartment were quantitated in wild-type neonatal mice or littermates over-expressing a labile (nonheparin binding) isoform of vascular endothelial growth factor (VEGF(120)) from the developing lens. This methodology was instructive in demonstrating that hyaloid vascular networks in VEGFA(120) over-expressing mice have a 10-fold increase in blind-ended, a six-fold increase in connected vessel segments, in addition to a sixfold increase (0.0314 versus 0.0051 mm(3)) in total vitreous vessel volume compared with wild type. These parameters are not readily quantified via histological, ultrastructural, or stereological analysis. CONCLUSION: The combination of techniques described here provides the first 3D quantitative characterization of vasculature in an organ system; i.e., the neonatal murine intra-ocular vasculature in both wild-type mice and a transgenic model of lens-specific over-expression of VEGF.

Mega aorta syndrome: a case of thoracic and abdominal aortic aneurysm.

An 83-year-old woman presented to the emergency department (ED) via emergency medical services with the chief complaint of "strokelike symptoms." Physical examination revealed altered mental status, tachycardia, hypotension, and a large nonpulsatile periumbilical mass. Bedside ultrasound revealed a 9-cm abdominal aortic aneurysm with absent central flow. Computed tomography scan demonstrated diffuse thoracic and abdominal aortic dilation with rupture into the mediastinum along with left hemothorax. Repeat beside ultrasound demonstrated abdominal aortic aneurysm rupture not seen on the computed tomography scan. Despite aggressive resuscitation, the patient developed bradycardia, which devolved into pulseless electric activity cardiac arrest. She was unable to be resuscitated. The patient's diffuse aneurysmal dilation places her into the small category of patients with a disease entity known as mega aorta syndrome (MAS). Mega aorta syndrome is defined as aneurysmal dilation of the aorta to greater than 6 cm in diameter. Although not in our case, most cases of MAS are symptomatic before catastrophic presentation. The disease progression for these patients is slow and occurs over years. When this disease is recognized early, a surgery known as the elephant trunk procedure can be performed. This operation replaces the entire aorta in multiple stages. This gives the emergency physician a critical role in the diagnosis and outcome of these patients because they may come through the ED for an unrelated complaint early in the disease process. This case report illustrates an advanced case of MAS.

Synchrotron X-ray microtomography for assessment of bone tissue scaffolds.

X-ray microtomography (microCT) is a popular tool for imaging scaffolds designed for tissue engineering applications. The ability of synchrotron microCT to monitor tissue response and changes in a bioactive glass scaffold ex vivo were assessed. It was possible to observe the morphology of the bone; soft tissue ingrowth and the calcium distribution within the scaffold. A second aim was to use two newly developed compression rigs, one designed for use inside a laboratory based microCT machine for continual monitoring of the pore structure and crack formation and another designed for use in the synchrotron facility. Both rigs allowed imaging of the failure mechanism while obtaining stress-strain data. Failure mechanisms of the bioactive glass scaffolds were found not to follow classical predictions for the failure of brittle foams. Compression strengths were found to be 4.5-6 MPa while maintaining an interconnected pore network suitable for tissue engineering applications.

US Army Combat Medic Performance With Portable Ultrasound to Detect Sonographic Findings of Pneumothorax in a Cadaveric Model.

BACKGROUND: Ultrasound, due to recent advances in portability and versatility, has become a valuable clinical adjunct in austere, resource-limited settings and is well demonstrated to be an accurate/efficient means to detect pneumothorax. The purpose of this study was to evaluate the impact of hands-on ultrasound training on ultrasound-naive US Army combat medics' ability to detect sonographic findings of pneumothorax with portable ultrasound in a cadaver model. METHODS: Ultrasound-naive US Army combat medics assigned to conventional military units were recruited from a single US Army installation and randomized to receive either didactic training only, or "blended" (didactic and hands-on) training on ultrasound detection of pneumothorax. Blinded participants were asked to perform a thoracic ultrasound exam on ventilated human cadaver models. Primary outcome measured was sensitivity and specificity of detecting sonographic findings of pneumothorax between cohorts. RESULTS: Forty-three participants examined a total of 258 hemithoraces. The didactic-only cohort (n = 24) detected sonographic findings of pneumothorax with a sensitivity of 68% and specificity of 57%. The blended cohort (n = 19) detected sonographic findings of pneumothorax with an overall sensitivity of 91% and specificity of 80%. Detection sensitivities were similar between B-mode versus M-mode use. CONCLUSION: US Army combat medics can use portable U/S to detect sonographic findings of pneumothorax in a human cadaver model with high sensitivity after a brief, blended (didactic and hands-on) training intervention.

Electrospinning 3D bioactive glasses for wound healing.

An electrospinning technique was used to produce three-dimensional (3D) bioactive glass fibrous scaffolds, in the SiO2-CaO sol-gel system, for wound healing applications. Previously, it was thought that 3D cotton wool-like structures could only be produced from sol-gel when the sol contained calcium nitrate, implying that the Ca2+ and its electronic charge had a significant effect on the structure produced. Here, fibres with a 3D appearance were also electrospun from compositions containing only silica. A polymer binding agent was added to inorganic sol-gel solutions, enabling electrospinning prior to bioactive glass network formation and the polymer was removed by calcination. While the addition of Ca2+ contributes to the 3D morphology, here we show that other factors, such as relative humidity, play an important role in producing the 3D cotton-wool-like macrostructure of the fibres. A human dermal fibroblast cell line (CD-18CO) was exposed to dissolution products of the samples. Cell proliferation and metabolic activity tests were carried out and a VEGF ELISA showed a significant increase in VEGF production in cells exposed to the bioactive glass samples compared to control in DMEM. A novel SiO2-CaO nanofibrous scaffold was created that showed tailorable physical and dissolution properties, the control and composition of these release products are important for directing desirable wound healing interactions.