Hypoxia as a stimulus for tissue formation: The concept of organogenesis in microsurgically vascularized tissue engineering constructs

Axial vascularization of tissue constructs is essential to maintain an adequate blood supply for a stable regeneration of a clinically relevant tissue size. The versatility of the arterio-venous loop (AVL) has been previously shown in various small and large animal models as well as in clinical reports for bone regeneration. We have previously demonstrated the capability of the AVL to induce axial vascularization and to support the nourishment of tissue constructs in small animal models after applying high doses of ionizing radiation comparable to those applied for adjuvant radiotherapy after head and neck cancer. We hypothesize that this robust ability to induce regeneration after irradiation could be related to a state of hypoxia inside the constructs that triggers the HIF1 (hypoxia induced factor 1) - SDF1 (stromal derived factor 1) axis leading to chemotaxis of progenitor cells and induction of tissue regeneration and vascularization. We analyzed the expression of HIF1 and SDF1 via immunofluorescence in axially vascularized bone tissue engineering constructs in Lewis rats 2 and 5 weeks after local irradiation with 9Gy or 15Gy. We also analyzed the expression of various genes for osteogenic differentiation (collagen 1, RUNX, alkaline phosphatase and osteonectin) via real time PCR analysis. The expression of HIF1 and SDF1 was enhanced two weeks after irradiation with 15Gy in comparison to non-irradiated constructs. The expression of osteogenic markers was enhanced at the 5-weeks time point with significant results regarding collagen, alkaline phosphatase and osteonectin. These results indicate that the hypoxia within the AVL constructs together with an enhanced SDF1 expression probably play a role in promoting tissue differentiation. The process of tissue generation triggered by hypoxia in the vicinity of a definite vascular axis with enhanced tissue differentiation over time resembles hereby the well-known concept of organogenesis in fetal life.

Indication-specific effect of a phytotherapeutic remedy on human fetal osteoblastic cells: An in-vitro analysis

Background Impaired fracture healing is a recurring interdisciplinary medical challenge. Alternative treatment concepts, apart from conventional medicine are popular, but scientific evidence on their effects is still lacking. Plant-derived substances are widely assumed to support bone homeostasis. To clarify the effects on bone healing mechanisms, a commercially available, homeopathic-spagyric remedy, containing inter alia two herbal substances with assumed osteogenic potential, equisetum arvense and bellis perennis, was analyzed. Methods Human fetal osteoblastic cells (hFOB1.19) were incubated with the test substance, in serial dilutions from 10 to 0,00001 %. Cell viability has been evaluated through ATP level (CTG assay) and MTT tetrazolium reduction. Cell proliferation was analyzed by BrdU incorporation and cell migration by wound healing assay (WHA) via image analysis. Additionally, determination of the expression of key genes via real-time PCR and proteins via Proteome Array for inflammation, cell proliferation and angiogenesis were performed. Results An incubation of hFOB 1.19 with the test substance for 24/72 hours showed no reduction in cell number, viability or proliferation. Cell migration was unimpaired. The test substance induced inflammatory genes and growth factors along with genes of osseous regeneration. (ALP, Col1, IL-1α, IL-6, IL-8, IL-10, Osteocalcin, Osteonectin, RUMX2, TGF, VEGFA). Increased protein expression was found in multiple cytokines, chemokines and acute phase proteins. Conclusion The test substance did not impair cell vitality parameters (MTT, CTG, BrdU and WHA). A tendency to activate growth factors, bone regeneration genes and proteins was shown for osteoblasts, indicating a possible positive effect on osteogenic processes.

Structural, chemical, and magnetic investigation of a graphene/cobalt/platinum multilayer system on silicon carbide

We investigate the magnetic interlayer coupling and domain structure of ultra-thin ferromagnetic (FM) cobalt (Co) layers embedded between a graphene (G) layer and a platinum (Pt) layer on a silicon carbide (SiC) substrate (G/Co/Pt on SiC). Experimentally, a combination of x-ray photoemission electron microscopy with x-ray magnetic circular dichroism has been carried out at the Co L-edge. Furthermore, structural and chemical properties of the system have been investigated using low energy electron diffraction (LEED) and x-ray photoelectron spectroscopy (XPS).In situLEED patterns revealed the crystalline structure of each layer within the system. Moreover, XPS confirmed the presence of quasi-freestanding graphene, the absence of cobalt silicide, and the appearance of two silicon carbide surface components due to Pt intercalation. Thus, the Pt-layer effectively functions as a diffusion barrier. The magnetic structure of the system was unaffected by the substrate's step structure. Furthermore, numerous vortices and anti-vortices were found in all samples, distributed all over the surfaces, indicating Dzyaloshinskii-Moriya interaction. Only regions with a locally increased Co-layer thickness showed no vortices. Moreover, unlike in similar systems, the magnetization was predominantly in-plane, so no perpendicular magnetic anisotropy was found.

Microporous Polylactic Acid Scaffolds Enable Fluorescence-Based Perfusion Imaging of Intrinsic In Vivo Vascularization

In vivo tissue engineering (TE) techniques like the AV loop model provide an isolated and well-defined microenvironment to study angiogenesis-related cell interactions. Functional visualization of the microvascular network within these artificial tissue constructs is crucial for the fundamental understanding of vessel network formation and to identify the underlying key regulatory mechanisms. To facilitate microvascular tracking advanced fluorescence imaging techniques are required. We studied the suitability of microporous polylactic acid (PLA) scaffolds with known low autofluorescence to form axial vascularized tissue constructs in the AV loop model and to validate these scaffolds for fluorescence-based perfusion imaging. Compared to commonly used collagen elastin (CE) scaffolds, the total number of vessels and cells in PLA scaffolds was lower. In detail, CE-based constructs exhibited significantly higher vessel numbers on day 14 and 28 (d14: 316 ± 53; d28: 610 ± 74) compared to the respective time points in PLA-based constructs (d14: 144 ± 18; d28: 327 ± 34; each p < 0.05). Analogously, cell counts in CE scaffolds were higher compared to corresponding PLA constructs (d14: 7661.25 ± 505.93 and 5804.04 ± 716.59; d28: 11211.75 + 1278.97 and 6045.71 ± 572.72, p < 0.05). CE scaffolds showed significantly higher vessel densities in proximity to the main vessel axis compared to PLA scaffolds (200-400 µm and 600-800 µm on day 14; 400-1000 µm and 1400-1600 µm on day 28). CE scaffolds had significantly higher cell counts on day 14 at distances from 800 to 2000 µm and at distances from 400 to 1600 µm on day 28. While the total number of vessels and cells in PLA scaffolds were lower, both scaffold types were ideally suited for axial vascularization techniques. The intravascular perfusion of PLA-based constructs with fluorescence dye MHI148-PEI demonstrated dye specificity against vascular walls of low- and high-order branches as well as capillaries and facilitated the fluorescence-based visualization of microcirculatory networks. Fluorophore tracking may contribute to the development of automated quantification methods after 3D reconstruction and image segmentation. These technologies may facilitate the characterization of key regulators within specific subdomains and add to the current understanding of vessel formation in axially vascularized tissue constructs.

Validation of a novel testing machine for the investigation of the biomechanical properties of lumbar vertebrae in an osteoporotic rat model

BACKGROUND

For the investigation of the biomechanical properties of bone, various testing devices have been described. However, only a limited number have been developed to test the vertebral body of small animals. The aim of this study was to develop and validate a new bone testing device, which investigates the different biomechanical properties in small-animal vertebrae as a whole, three-dimensional unit, respecting its anatomical structure.

METHODS

Thirty-five twelve-week-old female Sprague Dawley rats were utilized. Group 1 was composed of 17 rats with a normal bone metabolism without osteoporosis, while Group 2 consisted of 18 rats with manifest osteoporosis, 8 weeks after ovariectomy. The 5th lumbar vertebra of each animal was tested using the new bone testing device. This device has the ability to be adjusted to the slanted nature of each individual vertebral body and fix the vertebra in a natural position to allow for a non-dislocating axial force application. The device is designed to respect the anatomical three-dimensional shape of the vertebral body, thus avoiding the application of non-anatomic, non-physiological forces and thus preventing a distortion of the biomechanical testing results. The parameters investigated were stiffness, yield load, maximum load and failure load, and the results were compared to current literature values.

RESULTS

The conduction of the biomechanical bone testing of the vertebral bodies with the new device was conductible without any instances of dislocation of the vertebrae or machine malfunctions. Significant differences were found for stiffness, maximum load and failure load between groups, with a lower value in the osteoporotic rats in each parameter tested. The yield load was also lower in the osteoporotic group, however not significantly. The values achieved correlate with those in current literature.

CONCLUSIONS

This study demonstrates that the newly developed testing machine is easy to handle and produces valid data sets for testing biomechanical bone parameters of whole vertebral bodies in an established small animal model. Therefore, it can be utilized, also as reference data, to test different structural properties and changes in vertebral bone, for example, in different metabolic settings or under the influence of different pharmaceutical entities in further studies.

Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars

The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater's sedimentary delta, finding the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named Séítah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Fe-Mg carbonates along grain boundaries indicate reactions with CO₂-rich water, under water-poor conditions. Overlying Séítah is a unit informally named Máaz, which we interpret as lava flows or the chemical complement to Séítah in a layered igneous body. Voids in these rocks contain sulfates and perchlorates, likely introduced by later near-surface brine evaporation. Core samples of these rocks were stored aboard Perseverance for potential return to Earth.

Systemically injected bone marrow mononuclear cells specifically home to axially vascularized tissue engineering constructs

Inducing axial vascularisation of tissue engineering constructs is a well-established method to support tissue growth in large 3-dimensional tissues. Progenitor cell chemotaxis towards axially vascularized tissues has not been well characterized. In a prospective randomized controlled study including 32 male syngeneic Lewis rats we investigated the capability of the axially vascularized constructs to attract systemically injected bone marrow mononuclear cells (BMMNCs). The underlying mechanism for cell homing was investigated focusing on the role of hypoxia and the SDF1-CXCR4-7 axis. Sixteen animals were used as donors for BMMNCs. The other animals were subjected to implantation of a tissue engineering construct in the subcutaneous groin region. These constructs were axially vascularized either via an arteriovenous loop (AVL, n = 6) or via uninterrupted flow-through vessels (non-AVL, n = 10). BMMNCs were labelled with quantum dots (Qdot® 655) and injected 12 days after surgery either via intra-arterial or intravenous routes. 2 days after cell injection, the animals were sacrificed and examined using fluorescence microscopy. The Qdot® 655 signals were detected exclusively in the liver, spleen, AVL constructs and to a minimal extent in the non-AVL constructs. A significant difference could be detected between the number of labelled cells in the AVL and non-AVL constructs with more cells detected in the AVL constructs specially in central zones (p <0.0001). The immunohistological analysis showed a significant increase in the absolute expression of HIF-1 in the AVL group in comparison to the non-AVL group. The PCR analysis confirmed a 1.4-fold increase in HIF-1 expression in AVL constructs. Although PCR analysis showed an enhanced expression of CXCR4 and CXCR7 in AVL constructs, no significant differences in SDF1 expression were detected via immunohistological or PCR analysis. At the examined time point, the AVL constructs can attract BMMNCs in a mechanism probably related to the hypoxia associated with a robust tissue formation.

Expression of Connexin43 Stimulates Endothelial Angiogenesis Independently of Gap Junctional Communication In Vitro

Connexins (Cx) form gap junctions (GJ) and allow for intercellular communication. However, these proteins also modulate gene expression, growth, and cell migration. The downregulation of Cx43 impairs endothelial cell migration and angiogenetic potential. Conversely, endothelial Cx43 expression is upregulated in an in vivo angiogenesis model relying on hemodynamic forces. We studied the effects of Cx43 expression on tube formation and proliferation in HUVECs and examined its dependency on GJ communication. Expectedly, intercellular communication assessed by dye transfer was linked to Cx43 expression levels in HUVECs and was sensitive to a GJ blockade by the Cx43 mimetic peptide Gap27. The proliferation of HUVECs was not affected by Cx43 overexpression using Cx43 cDNA transfection, siRNA-mediated knockdown of Cx43, or the inhibition of GJ compared to the controls (transfection of an empty vector, scrambled siRNA, and the solvent). In contrast, endothelial tube and sprout formation in HUVECs was minimized after Cx43 knockdown and significantly enhanced after Cx43 overexpression. This was not affected by a GJ blockade (Gap27). We conclude that Cx43 expression positively modulates the angiogenic potential of endothelial cells independent of GJ communication. Since proliferation remained unaffected, we suggest that Cx43 protein may modulate endothelial cell migration, thereby supporting angiogenesis. The modulation of Cx43 expression may represent an exploitable principle for angiogenesis induction in clinical therapy.

0801 Sleep, Nightmares, and the Maintenance of Posttrauma Symptoms

Introduction

Most individuals will experience at least one traumatic event in their lifetime. Although most individuals who experience a trauma will exhibit some posttrauma symptoms, only a small subset will experience long-lasting symptoms. In fact, most research suggests that posttrauma symptoms will gradually reduce over time. However, some individuals can exhibit posttrauma symptoms for an extended period of time. Although research has demonstrated that poor overall sleep quality may explain why some people have trouble gradually recovering from posttrauma symptoms, research has yet to examine specific aspects of sleep that can impair the gradual remission of posttrauma symptoms. This study examined how individual facets of sleep quality (such as nightmares and sleep duration) impact posttrauma symptoms over time.

Methods

944 college students completed an online survey battery that included measures of traumatic experiences, time since trauma (TST), posttrauma symptoms, sleep quality, and the presence of nightmares. Regression analyses were used to examine the interaction of sleep quality sub-facets and time since trauma on posttrauma nightmares (PNMs).

Results

Out of 944 participants, 637 (67%) reported at least one trauma. Of those students, time since trauma (TST) and all other sleep variables significantly predicted posttrauma symptoms (p &lt; 0.05). However, the only significant interaction was nightmares and TST (p &lt; 0.01) where individuals who experienced PNMs had significantly (p &lt; 0.01) higher posttrauma symptom intercept (48.19) than individuals who did not experience PNMs (31.19). Furthermore, individuals who experienced PNMs demonstrated statistically significant flatter slopes than those without nightmares (p &lt; 0.01).

Conclusion

The results reveal that time since trauma predicts a decrease in posttrauma symptoms, whereas nightmares impede this symptom reduction. Interestingly, the interaction finding suggests that nightmares play a critical role in initial symptom expression and recovery. These results demonstrate the importance of identifying and treating nightmares immediately following a trauma.

Support

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Robust and Resource-Efficient Microwave Near-Field Entangling ^{9}Be^{+} Gate

Microwave trapped-ion quantum logic gates avoid spontaneous emission as a fundamental source of decoherence. However, microwave two-qubit gates are still slower than laser-induced gates and hence more sensitive to fluctuations and noise of the motional mode frequency. We propose and implement amplitude-shaped gate drives to obtain resilience to such frequency changes without increasing the pulse energy per gate operation. We demonstrate the resilience by noise injection during a two-qubit entangling gate with ^{9}Be^{+} ion qubits. In the absence of injected noise, amplitude modulation gives an operation infidelity in the 10^{-3} range.

Impact of body mass index on 30-day postoperative morbidity in pediatric and adolescent patients undergoing continent urinary tract reconstruction

INTRODUCTION

Obesity has been thought to increase the risk of complications and need for additional resources with surgery, but only a limited amount of evidence is available in the pediatric population.

OBJECTIVE

The objectives were to describe the weight status of pediatric and adolescent patients undergoing a continent urinary tract reconstruction and to determine the association between obesity and 30-day postoperative morbidity.

STUDY DESIGN

A retrospective cohort study was performed for pediatric and adolescent patients aged up to 20 years who underwent a continent urinary tract reconstruction between January 2010 and November 2016. Weight status was stratified by the body mass index (BMI) for age z-scores as follows: underweight (<5th percentile), normal (5th to <85th percentiles), overweight (85th to <95th percentiles), and obese (≥95th percentile). Primary outcomes included the duration of intensive care and hospitalization as well as re-admissions and complications within 30 days.

RESULTS

A total of 182 continent reconstructions were identified during the study period. Demographic and peri-operative data are provided in the Table. Weight status was not associated with any primary outcomes on univariate or multivariate analysis. There was also no association in an analysis between the non-overweight or non-obese group (BMI for age z-score <85th) and overweight or obese group (BMI for age z-score ≥85th percentiles); a subgroup analysis between patients with and without myelomeningocele; or a subgroup analysis for wound, infectious, or high-grade (Clavien-Dindo grades III or higher) complications.

DISCUSSION

Obesity has been consistently associated with an increased risk of surgical site infections and wound complications after a wide variety of surgeries in adults. The results from the present study conflict with those of the few available studies in the pediatric population. The high-risk nature of the present cohort may have mitigated any effect of obesity on 30-day postoperative morbidity. The limitations of the present study include its retrospective design at a single center and the potential misclassification of weight status with the BMI.

CONCLUSIONS

Almost 30% of pediatric and adolescent patients undergoing a continent urinary tract reconstruction were overweight or obese. Obesity as determined by the BMI was not associated with 30-day postoperative morbidity.

MicroRNA-regulated pathways of flow-stimulated angiogenesis and vascular remodeling in vivo

BACKGROUND

Vascular shear stress promotes endothelial cell sprouting in vitro. The impact of hemodynamic forces on microRNA (miRNA) and gene expression within growing vascular networks in vivo, however, remain poorly investigated. Arteriovenous (AV) shunts are an established model for induction of neoangiogenesis in vivo and can serve as a tool for analysis of hemodynamic effects on miRNA and gene expression profiles over time.

METHODS

AV shunts were microsurgically created in rats and explanted on postoperative days 5, 10 and 15. Neoangiogenesis was confirmed by histologic analysis and micro-computed tomography. MiRNA and gene expression profiles were determined in tissue specimens from AV shunts by microarray analysis and quantitative real-time polymerase chain reaction and compared with sham-operated veins by bioinformatics analysis. Changes in protein expression within AV shunt endothelial cells were determined by immunohistochemistry.

RESULTS

Samples from AV shunts exhibited a strong overexpression of proangiogenic cytokines, oxygenation-associated genes (HIF1A, HMOX1), and angiopoetic growth factors. Significant inverse correlations of the expressions of miR-223-3p, miR-130b-3p, miR-19b-3p, miR-449a-5p, and miR-511-3p which were up-regulated in AV shunts, and miR-27b-3p, miR-10b-5p, let-7b-5p, and let-7c-5p, which were down-regulated in AV shunts, with their predicted interacting targets C-X-C chemokine receptor 2 (CXCR2), interleukin-1 alpha (IL1A), ephrin receptor kinase 2 (EPHA2), synaptojanin-2 binding protein (SYNJ2BP), forkhead box C1 (FOXC1) were present. CXCL2 and IL1A overexpression in AV shunt endothelium was confirmed at the protein level by immunohistochemistry.

CONCLUSIONS

Our data indicate that flow-stimulated angiogenesis is determined by an upregulation of cytokines, oxygenation associated genes and miRNA-dependent regulation of FOXC1, EPHA2 and SYNJ2BP.

Irradiation Delays Tissue Growth but Enhances Osteogenic Differentiation in Vascularized Constructs

BACKGROUND

 Regenerative medicine is still deficient in the reconstruction after cancer due to impaired vascularization after radiotherapy and due to the need to substitute larger defects after tumor excision. Aiming at introducing regenerative medicine for reconstruction after cancer, we tested an axially vascularized bone construct in an experimental setting that mimics the clinical situation after tumor resection and adjuvant radiotherapy.

METHODS

 Twenty bone constructs were axially vascularized using microsurgically created arteriovenous loops and were implanted subcutaneously in Lewis rats. After 2 weeks, the animals were randomly allocated either to receive a clinically relevant single dose of external beam irradiation or not (n = 10 for each group). The animals were sacrificed either after 1 week or 10 weeks after irradiation (n = 5 for each time point). The constructs were tested for vascularization, tissue growth, cellular proliferation, cellular apoptosis, and osteogenic differentiation via histomorphometric, immunohistochemical, and polymerase chain reaction (PCR) analysis. One construct per group was subjected at 10 weeks to qualitative micro-computed tomography (CT) imaging.

RESULTS

 Tissue generation and cellular proliferation were significantly reduced at 1 week after irradiation, but no longer significantly different after 10 weeks.No significant differences in vascularization were detected at any time point. Apoptosis did not show any statistically significant differences between both groups at both time points. At the late time point, mature bone was considerably more in the irradiated group, but the results were not statistically significant. PCR analysis showed a significantly enhanced expression of osteocalcin in the irradiated group at 1 week. Micro-CT imaging showed that both constructs were adequately vascularized with no evident morphologic differences regarding vascular density or vascular distribution.

CONCLUSIONS

 Axially vascularized bone constructs can withstand clinically relevant doses of irradiation and retain their angiogenic and osteogenic potential in the long term. Irradiation led to a delayed tissue generation with a comparatively enhanced osteogenic differentiation within the constructs.

Preliminary report: Surgical outcomes following genitoplasty in children with moderate to severe genital atypia

INTRODUCTION

Prior studies of outcomes following genitoplasty have reported high rates of surgical complications among children with atypical genitalia. Few studies have prospectively assessed outcomes after contemporary surgical approaches.

OBJECTIVE

The current study reported the occurrence of early postoperative complications and of cosmetic outcomes (as rated by surgeons and parents) at 12 months following contemporary genitoplasty procedures in children born with atypical genitalia.

STUDY DESIGN

This 11-site, prospective study included children aged ≤2 years, with Prader 3-5 or Quigley 3-6 external genitalia, with no prior genitoplasty and non-urogenital malformations at the time of enrollment. Genital appearance was rated on a 4-point Likert scale. Paired t-tests evaluated differences in cosmesis ratings.

RESULTS

Out of 27 children, 10 were 46,XY patients with the following diagnoses: gonadal dysgenesis, PAIS or testosterone biosynthetic defect, severe hypospadias and microphallus, who were reared male. Sixteen 46,XX congenital adrenal hyperplasia patients were reared female and one child with sex chromosome mosaicism was reared male. Eleven children had masculinizing genitoplasty for penoscrotal or perineal hypospadias (one-stage, three; two-stage, eight). Among one-stage surgeries, one child had meatal stenosis (minor) and one developed both urinary retention (minor) and urethrocutaneous fistula (major) (Summary Figure). Among two-stage surgeries, three children developed a major complication: penoscrotal fistula, glans dehiscence or urethral dehiscence. Among 16 children who had feminizing genitoplasty, vaginoplasty was performed in all, clitoroplasty in nine, external genitoplasty in 13, urethroplasty in four, perineoplasty in five, and total urogenital sinus mobilization in two. Two children had minor complications: one had a UTI, and one had both a mucosal skin tag and vaginal mucosal polyp. Two additional children developed a major complication: vaginal stenosis. Cosmesis scores revealed sustained improvements from 6 months post-genitoplasty, as previously reported, with all scores reported as good or satisfied.

DISCUSSION

In these preliminary data from a multi-site, observational study, parents and surgeons were equally satisfied with the cosmetic outcomes 12 months after genitoplasty. A small number of patients had major complications in both feminizing and masculinizing surgeries; two-stage hypospadias repair had the most major complications. Long-term follow-up of patients at post-puberty will provide a better assessment of outcomes in this population.

CONCLUSION

In this cohort of children with moderate to severe atypical genitalia, preliminary data on both surgical and cosmetic outcomes were presented. Findings from this study, and from following these children in long-term studies, will help guide practitioners in their discussions with families about surgical management.

Low-energy extracorporeal shockwave therapy (ESWT) improves metaphyseal fracture healing in an osteoporotic rat model

Purpose

As result of the current demographic changes, osteoporosis and osteoporotic fractures are becoming an increasing social and economic burden. In this experimental study, extracorporeal shock wave therapy (ESWT), was evaluated as a treatment option for the improvement of osteoporotic fracture healing.

Methods

A well-established fracture model in the metaphyseal tibia in the osteoporotic rat was used. 132 animals were divided into 11 groups, with 12 animals each, consisting of one sham-operated group and 10 ovariectomized (osteoporotic) groups, of which 9 received ESWT treatment. Different energy flux intensities (0.15 mJ/mm², 0.35 mJ/mm², or 0.55 mJ/mm²) as well as different numbers of ESWT applications (once, three times, or five times throughout the 35-day healing period) were applied to the osteoporotic fractures. Fracture healing was investigated quantitatively and qualitatively using micro-CT imaging, quantitative real-time polymerase chain reaction (qRT-PCR) analysis, histomorphometric analysis and biomechanical analysis.

Results

The results of this study show a qualitative and quantitative improvement in the osteoporotic fracture healing under low-energy (energy flux intensity: 0,15 mJ/mm²) ESWT and with fewer treatment applications per healing period.

Conclusion

In conclusion, low-energy ESWT seems to exhibit a beneficial effect on the healing of osteoporotic fractures, leading to improved biomechanical properties, enhanced callus-quantity and -quality, and an increase in the expression of bone specific transcription factors. The results suggest that low-energy ESWT, as main treatment or as adjunctive treatment in addition to a surgical intervention, may prove to be an effective, simple to use, and cost-efficient option for the qualitative and quantitative improvement of osteoporotic fracture healing.

Age-dependent alterations in osteoblast and osteoclast activity in human cancellous bone

It is assumed that the activity of osteoblasts and osteoclasts is decreased in bone tissue of aged individuals. However, detailed investigation of the molecular signature of human bone from young compared to aged individuals confirming this assumption is lacking. In this study, quantitative expression analysis of genes related to osteogenesis and osteoclastogenesis of human cancellous bone derived from the distal radius of young and aged individuals was performed. Furthermore, we additionally performed immunohistochemical stainings. The young group included 24 individuals with an average age of 23.2 years, which was compared to cancellous bone derived from 11 body donators with an average age of 81.0 years. In cancellous bone of young individuals, the osteogenesis-related genes RUNX-2, OSTERIX, OSTEOPONTIN and OSTEOCALCIN were significantly up-regulated compared to aged individuals. In addition, RANKL and NFATc1, both markers for osteoclastogenesis, were significantly induced in cancellous bone of young individuals, as well as the WNT gene family member WNT5a and the matrix metalloproteinases MMP-9. However, quantitative RT-PCR analysis of BMP-2, ALP, FGF-2, CYCLIN-D1, MMP-13, RANK, OSTEOPROTEGERIN and TGFb1 revealed no significant difference. Furthermore, Tartrate-resistant acid phosphatase (TRAP) staining was performed which indicated an increased osteoclast activity in cancellous bone of young individuals. In addition, pentachrome stainings revealed significantly less mineralized bone matrix, more osteoid and an increased bone density in young individuals. In summary, markers related to osteogenesis as well as osteoclastogenesis were significantly decreased in the aged individuals. Thus, the present data extends the knowledge about reduced bone regeneration and healing capacity observed in aged individuals.

Effective and rapid treatment of wound botulism, a case report

Background

The latest news shows several cases of contaminated heroin that is found in different parts all over Europe. This information can be helpful for the emergency doctors to find the correct diagnosis of wound botulism in patients who are intravenous drug users.

Case presentation

We describe a case of a 40-year-old man who presented to the emergency department in 2016. He suffered from mild dysarthria, diplopia, dysphagia and ptosis since two days. The CT-scan of the cerebrum and the liquor were without any pathological results. We found out that the patient is an intravenous drug user and the clinical examination showed an abscess in the left groin. So we treated him with the suspected diagnosis of wound botulism.

In the emergency operation we split the abscess, made a radical debridement and complementary treated him with a high dose of penicillin g and two units of botulism antitoxin. The suspected diagnosis was confirmed a few days later by finding the Toxin B in the abscess and in the patient’s serum. In the following days the neurological symptoms decreased and the wound healing was without any complications. The patient left the hospital after nine days; the antibiotic therapy with penicillin g was continued for several days. In a following examination, 14 days after the patient’s discharge of the hospital, no further symptoms were found and the abscess was treated successfully without any problems.

Conclusion

Because wound botulism is a very rare disease it can be challenging to the attending physician. This case shows a fast treatment with full recovery of the patient without any further disabilities, which can be used for the future.

Clinical and urodynamic outcomes in children with anorectal malformation subtype of recto-bladder neck fistula

INTRODUCTION

Patients with anorectal malformations (ARMs) have a high incidence of genitourinary anomalies. Those with a recto-bladder neck fistula may represent a high-risk group, but their long-term urologic outcomes are poorly described.

OBJECTIVE

To evaluate the clinical and urodynamic outcomes in a large cohort of patients with an ARM subtype of recto-bladder neck fistula.

MATERIALS AND METHODS

A retrospective cohort study was performed of patients who had been treated for a recto-bladder neck fistula at the present institution since 2007. The primary outcomes were the ability to achieve urinary continence after 4 years of age, and development of a mildly decreased glomerular filtration rate (GFR) or worse (<89 ml/min/1.73 m²). Continence was defined as the ability to store urine for 3-4 h during the day and 8 h overnight without leakage.

RESULTS

Demographic and clinical data are provided in the Summary Table. The most recent urodynamic findings included the presence of detrusor overactivity in 30 (75%) patients, median leak point pressure of 56.0 cmH₂O (range, 14-140), median functional cystometric capacity at 40 cmH₂O of 125.5% age-expected capacity (range, 36-473%), and median maximum cystometric capacity of 131.0% age-expected capacity (range, 44-473%). A mildly decreased GFR or worse developed in 13 (24%) patients. Of the 52 (78%) patients who were followed by pediatric urology at the present institution with a median follow-up of 30.9 months (range, 0.0-86.8), 35 (67%) were at least 4 years of age and could be assessed for continence. Continence was achieved in five (14%) patients voiding spontaneously and 15 (43%) performing CIC. Recurrent urinary tract infections (UTI) (OR 0.70, P = 0.006) were an independent predictor of incontinence, while urethral anomalies (OR 1.40, P = 0.03) were an independent predictor of chronic kidney disease (CKD) on multiple logistic regression analysis.

DISCUSSION

The findings favorably compared with other studies, but were more robust due to the size of the cohort and breadth of urologic evaluation. Limitations included the retrospective design at a single institution. Incomplete clinical data and misclassification of continence may have lead to bias.

CONCLUSIONS

This large cohort of patients with an ARM subtype of recto-bladder neck fistula had a high incidence of genitourinary anomalies. They were rarely able to achieve continence with spontaneous voiding alone and were at risk of developing CKD, both of which were likely multifocal in origin. Long-term urologic follow-up is warranted for patients with a recto-bladder neck fistula.

Axially vascularized tissue-engineered bone constructs retain their in vivo angiogenic and osteogenic capacity after high-dose irradiation

In order to introduce bone tissue engineering to the field of oncological reconstruction, we are investigating for the first time the effect of various doses of ionizing irradiation on axially vascularized bone constructs. Synthetic bone constructs were created and implanted in 32 Lewis rats. Each construct was axially vascularized through an arteriovenous loop made by direct anastomosis of the saphenous vessels. After 2 weeks, the animals received ionizing irradiation of 9 Gy, 12 Gy and 15 Gy, and were accordingly classified to groups I, II and III, respectively. Group IV was not irradiated and acted as a control. Tissue generation, vascularity, cellular proliferation and apoptosis were investigated either 2 or 5 weeks after irradiation through micro-computed tomography, histomorphometry and real-time polymerase chain reaction (PCR). At 2 weeks after irradiation, tissue generation and central vascularity were significantly lower and apoptosis was significantly higher in groups II and III than group IV, but without signs of necrosis. Cellular proliferation was significantly lower in groups I and II. After 5 weeks, the irradiated groups showed improvement in all parameters in relation to the control group, indicating a retained capacity for angiogenesis after irradiation. PCR results confirmed the expression of osteogenesis-related genes in all irradiated groups. Dense collagen was detected 5 weeks after irradiation, and one construct showed discrete islands of bone indicating a retained osteogenic capacity after irradiation. This demonstrates for the first time that axial vascularization was capable of supporting a synthetic bone construct after a high dose of irradiation that is comparable to adjuvant radiotherapy. Copyright © 2016 John Wiley & Sons, Ltd.

Prospective assessment of cosmesis before and after genital surgery

INTRODUCTION

Little data exist about the surgical interventions taking place for children with disorders of sex development (DSD). Most studies that have evaluated cosmetic outcomes after genitoplasty have included retrospective ratings by a physician at a single center.

OBJECTIVE

The present study aimed to: 1) describe frequency of sex assignment, and types of surgery performed in a cohort of patients with moderate-to-severe genital ambiguity; and 2) prospectively determine cosmesis ratings by parents and surgeons before and after genital surgery.

STUDY DESIGN

This prospective, observational study included children aged <2 years of age, with no prior genitoplasty at the time of enrollment, moderate-to-severe genital atypia, and being treated at one of 11 children's hospitals in the United States of America (USA). Clinical information was collected, including type of surgery performed. Parents and the local pediatric urologist rated the cosmetic appearance of the child's genitalia prior to and 6 months after genitoplasty.

RESULTS

Of the 37 children meeting eligibility criteria, 20 (54%) had a 46,XX karyotype, 15 (40%) had a 46,XY karyotype, and two (5%) had sex chromosome mosaicism. The most common diagnosis overall was congenital adrenal hyperplasia (54%). Thirty-five children had surgery; 21 received feminizing genitoplasty, and 14 had masculinizing genitoplasty. Two families decided against surgery. At baseline, 22 mothers (63%), 14 fathers (48%), and 35 surgeons (100%) stated that they were dissatisfied or very dissatisfied with the appearance of the child's genitalia. Surgeons rated the appearance of the genitalia significantly worse than mothers (P < 0.001) and fathers (P ≤ 0.001) at baseline. At the 6-month postoperative visit, cosmesis ratings improved significantly for all groups (P < 0.001 for all groups). Thirty-two mothers (94%), 26 fathers (92%), and 31 surgeons (88%) reported either a good outcome, or they were satisfied (see Summary Figure); there were no significant between-group differences in ratings.

DISCUSSION

This multicenter, observational study showed surgical interventions being performed at DSD centers in the USA. While parent and surgeon ratings were discordant pre-operatively, they were generally concordant postoperatively. Satisfaction with postoperative cosmesis does not necessarily equate with satisfaction with the functional outcome later in life.

CONCLUSION

In this cohort of children with genital atypia, the majority had surgery. Parents and surgeons all rated the appearance of the genitalia unfavorably before surgery, with surgeons giving worse ratings than parents. Cosmesis ratings improved significantly after surgery, with no between-group differences.

GRAND-4: the German retrospective analysis of long-term persistence in women with osteoporosis treated with bisphosphonates or denosumab

This retrospective database study assessed 2-year persistence with bisphosphonates or denosumab in a large German cohort of women with a first-time prescription for osteoporosis treatment. Compared with intravenous or oral bisphosphonates, 2-year persistence was 1.5-2 times higher and risk of discontinuation was significantly lower (P < 0.0001) with denosumab.

INTRODUCTION

Persistence with osteoporosis therapies is critical for fracture risk reduction. Detailed data on long-term persistence (≥2 years) with bisphosphonates and denosumab are sparse.

METHODS

From the German IMS® database, we included women aged 40 years or older with a first-time prescription for bisphosphonates or denosumab between July 2010 and August 2014; patients were followed up until December 2014. The main outcome was treatment discontinuation, with a 60-day permissible gap between filled prescriptions. Two-year persistence was estimated using Kaplan-Meier survival curves, with treatment discontinuation as the failure event. Denosumab was compared with intravenous (i.v.) and oral bisphosphonates separately. Cox proportional hazard ratios (HRs) for the 2-year risk of discontinuation were calculated, with adjustment for age, physician specialty, health insurance status, and previous medication use.

RESULTS

Two-year persistence with denosumab was significantly higher than with i.v. or oral bisphosphonates (39.8 % [n = 21,154] vs 20.9 % [i.v. ibandronate; n = 20,472] and 24.8 % [i.v. zoledronic acid; n = 3966] and 16.7-17.5 % [oral bisphosphonates; n = 114,401]; all P < 0.001). Patients receiving i.v. ibandronate, i.v. zoledronic acid, or oral bisphosphonates had a significantly increased risk of treatment discontinuation than did those receiving denosumab (HR = 1.65, 1.28, and 1.96-2.02, respectively; all P < 0.0001).

CONCLUSIONS

Two-year persistence with denosumab was 1.5-2 times higher than with i.v. or oral bisphosphonates, and risk of discontinuation was significantly lower with denosumab than with bisphosphonates. A more detailed understanding of factors affecting medication-taking behavior may improve persistence and thereby reduce rates of fracture.

Prevalence of antiretroviral drug resistance in the HIV-1-infected urban indigent population in San Francisco: a representative study

We determined the prevalence of antiretroviral (ARV) resistance in HIV-1 infected indigent persons in San Francisco, California. Three hundred and twenty-seven subjects (159 (49%) ARV naïve, and 168 (51%) ARV-experienced), were recruited during 1996–97 and 1999–2000. Plasma HIV-1 viral load quantification and genotypic resistance testing were performed. Twice as many subjects received nucleoside reverse transcriptase inhibitors (NRTIs) as non-nucleoside reverse transcriptase inhibitors (NNRTIs) or protease inhibitors (PIs); resistance mutation prevalences were 30%, 14% and 16% respectively. Risk of any resistance mutations was strongly and independently associated with prior ARV exposure (OR = 1.3 per year of exposure, P < 0.0001) and with ARV exposure prior to HAART (OR = 2.5, P = 0.015). Prevalences of primary ARV resistance mutations among both treatment-naive and treatment-experienced subjects in this indigent urban population are low compared to other observational cohorts, are directly related to length and type of prior ARV exposure, and did not increase significantly between recruitment periods.

Risk Factors Associated with HCV Among Opioid-Dependent Patients in a Multisite Study

We examined risk factors associated with hepatitis C virus (HCV) infection among opioid-dependent patients enrolled into medication-assisted therapy (buprenorphine or methadone) to determine factors affecting chronic infection. Patients (N = 1039) were randomized as part of a larger, multisite clinical trial sponsored by the National Drug Abuse Treatment Clinical Trials Network assessing liver function. HCV status was first assessed with an antibody screen; if positive, then current infection was determined with an antigen screen testing for detectable virus. Patients were classified as HCV negative, HCV positive but have cleared the virus, or as having chronic HCV. Logistic regression analysis was used to examine demographic and behavioral correlates of the three groups. Thirty-four percent of patients were classified with chronic infection and 14% had evidence of prior infection with apparent clearing of the virus. Chronic infection was associated with recent injection drug use and cocaine use. Chronic HCV infection was also associated with being older and Hispanic. Age, ethnicity, and current drug use increase the likelihood of being chronically infected with HCV. Strategies targeting high risk subgroups can aid in preventing further disease escalation.

Moments and Central Limit Theorems for Some Multivariate Poisson Functionals

This paper deals with Poisson processes on an arbitrary measurable space. Using a direct approach, we derive formulae for moments and cumulants of a vector of multiple Wiener-Itô integrals with respect to the compensated Poisson process. Also, we present a multivariate central limit theorem for a vector whose components admit a finite chaos expansion of the type of a Poisson U-statistic. The approach is based on recent results of Peccati et al. (2010), combining Malliavin calculus and Stein's method; it also yields Berry-Esseen-type bounds. As applications, we discuss moment formulae and central limit theorems for general geometric functionals of intersection processes associated with a stationary Poisson process of k-dimensional flats in .

Quantum Algorithmic Readout in Multi-Ion Clocks

Optical clocks based on ensembles of trapped ions promise record frequency accuracy with good short-term stability. Most suitable ion species lack closed transitions, so the clock signal must be read out indirectly by transferring the quantum state of the clock ions to cotrapped logic ions of a different species. Existing methods of quantum logic readout require a linear overhead in either time or the number of logic ions. Here we describe a quantum algorithmic readout whose overhead scales logarithmically with the number of clock ions in both of these respects. The scheme allows a quantum nondemolition readout of the number of excited clock ions using a single multispecies gate operation which can also be used in other areas of ion trap technology such as quantum information processing, quantum simulations, metrology, and precision spectroscopy.

Accuracy and precision of direct bone conduction measurements

OBJECTIVES

Variability in Baha® sound processor fittings arise from several sources including the nature of the implant-to-bone transmission and transcranial attenuation in patients with single-sided sensorineural deafness. One method of improving the predictability of Baha fittings is to measure the individual patient's actual bone conduction thresholds via the implant, thereby removing the influence of skin thickness and/or implant location site.

METHODOLOGY

One hundred thirty eight adult wearers of the Baha System participated in the study. Direct bone conduction thresholds were obtained through the BC Direct feature of the Cochlear™ Baha Fitting Software combined with the CochlearBaha BP100 sound processor. Test-retest reliability measurement was performed in 58 participants.

RESULTS

Improved transmission of sound through the implant rather than transcutaneously through the skin was confirmed. On average, the BC Direct thresholds were closer to the patient's unmasked thresholds than the masked values. In patients with single-sided sensorineural deafness, BC Direct results were elevated compared to the contralateral bone conduction thresholds due to transcranial attenuation. The test-retest reliability for the BC Direct measurements was within ±5 dB, which is in within the accepted variability for audiometric test measurements.

CONCLUSIONS

Direct bone conduction measurement provides a validated method of comparing the transcutaneous thresholds as measured through audiometry with the percutaneous responses from the Baha sound processor. The Baha fitting based on direct measurements of bone conduction may require less fine-tuning and provide a greater understanding of the variability of the bone conduction sound pathway.

Human scaphoid non-unions exhibit increased osteoclast activity compared to adjacent cancellous bone

Scaphoid bones have a high prevalence for non-union. Even with adequate treatment, bone regeneration may not occur in certain instances. Although this condition is well described, the molecular pathology of scaphoid non-unions is still poorly defined. In this study, gene expression of osteogenic and angiogenic growth and transcription factors as well as inflammatory mediators were analysed in human scaphoid non-unions and intraindividually compared to adjacent autologous cancellous bone from the distal radius. In addition, histology and immunohistochemical stainings were performed to verify qRT-PCR data. Gene expression analysis revealed a significant up-regulation of RANKL, ALP, CYCLIN D1, MMP-13, OPG, NFATc1, TGF-β and WNT5A in scaphoid non-unions. Interestingly, RANKL and NFATc1, both markers for osteoclastogenesis, were significantly induced in non-unions. Moreover, WNT5A was highly up-regulated in all non-union samples. TRAP staining confirmed the observation of induced osteoclastogenesis in non-unions. With respect to genes related to osteogenesis, alkaline phosphatase was significantly up-regulated in scaphoid non-unions. No differences were detectable for other osteogenic genes such as RUNX-2 or BMP-2. Importantly, we did not detect differences in angiogenesis between scaphoid non-unions and controls in both gene expression and immunohistochemistry. Summarized, our data indicate increased osteoclast activity in scaphoid non-unions possibly as a result of the alterations in RANKL, TGF-β and WNT5A expression levels. These data increase our understanding for the reduced bone regeneration capacity present in scaphoid non-unions and may translate into the identification of new therapeutic targets to avoid secondary damages and prevent occurrence of non-unions to scaphoid bones.

Application of VEGFA and FGF-9 enhances angiogenesis, osteogenesis and bone remodeling in type 2 diabetic long bone regeneration

Although bone regeneration is typically a reliable process, type 2 diabetes is associated with impaired or delayed healing processes. In addition, angiogenesis, a crucial step in bone regeneration, is often altered in the diabetic state. In this study, different stages of bone regeneration were characterized in an unicortical bone defect model comparing transgenic type 2 diabetic (db^-/db^-) and wild type (WT) mice in vivo. We investigated angiogenesis, callus formation and bone remodeling at early, intermediate and late time points by means of histomorphometry as well as protein level analyses. In order to enhance bone regeneration, defects were locally treated with recombinant FGF-9 or VEGFA. Histomorphometry of aniline blue stained sections indicated that bone regeneration is significantly decreased in db^-/db^- as opposed to WT mice at intermediate (5 days post operation) and late stages (7 days post operation) of bone regeneration. Moreover, immunohistochemical analysis revealed significantly decreased levels of RUNX-2, PCNA, Osteocalcin and PECAM-1 in db^-/db^- defects. In addition, osteoclastogenesis is impaired in db^-/db^- indicating altered bone remodeling. These results indicate significant impairments in angiogenesis and osteogenesis in type 2 diabetic bones. Importantly, angiogenesis, osteogenesis and bone remodeling could be reconstituted by application of recombinant FGF-9 and, in part, by VEGFA application. In conclusion, our study demonstrates that type 2 diabetes affects angiogenesis, osteogenesis and subsequently bone remodeling, which in turn leads to decreased bone regeneration. These effects could be reversed by local application of FGF-9 and to a lesser degree VEGFA. These data could serve as a basis for future therapeutic applications aiming at improving bone regeneration in the type 2 diabetic patient population.

Multiple extracorporeal shock wave therapy degrades capsular fibrosis after insertion of silicone implants

Capsular fibrosis is the most frequent long-term complication after insertion of silicone devices. Today, mainly direct immunostimulation and subclinical infection are held responsible for inducing and maintaining inflammatory reactions, which lead to overwhelming extracellular matrix formation. Extracorporeal shock waves (ESWs) are capable of inhibiting inflammatory processes and revealing antibacterial capacity. In our previous study, we observed decelerated capsule development after application of a single shock wave immediately after surgery. The purpose of this study was to evaluate the effects of multiple ESWT after insertion of silicone implants in the same rodent model. Therefore, silicone prostheses were inserted into a submuscular pocket in 12 additional male Lewis rats, and shock waves were administered over a 14-d interval. At 35 d (n = 6) and 100 d (n = 6) after insertion, silicone implants and surrounding capsule tissue were removed and prepared for histologic and immunohistochemical analysis, as well as polymerase chain reaction (Ccl2, CD68, transforming growth factor β1, matrix metalloproteinase 2). Compared with the control group, multiple ESWT had no effect on day 35, but resulted in a significantly thinner capsule on day 100 (825.8 ± 313.2 vs. 813.3 ± 47.9, p = 0.759, and 1062.3 ± 151.9 vs. 495.4 ± 220.4, p < 0.001, respectively). The capsule was even thinner than after a single shock wave application, which had been found to result in thinner capsules at every time point in our previous study. This active degradation of the fibrous envelope caused by multiple ESWs was accompanied by synergistic alterations in pro- and anti-fibrotic proteins (transforming growth factor β1 and matrix metalloproteinase 2, respectively). In conclusion, after insertion of silicone devices, single ESWT is capable of decelerating capsule formation in contrast to multiple ESWT, which degrades fibrotic tissue. These findings seem to be associated with inhibition of inflammation and beneficial effects on pro- and anti-fibrotic proteins.

Mixed dimensionality of confined conducting electrons in the surface region of SrTiO3

Using angle-resolved photoemission spectroscopy, we show that the recently discovered surface state on SrTiO(3) consists of nondegenerate t(2g) states with different dimensional characters. While the d(xy) bands have quasi-2D dispersions with weak k(z) dependence, the lifted d(xz)/d(yz) bands show 3D dispersions that differ significantly from bulk expectations and signal that electrons associated with those orbitals permeate the near-surface region. Like their more 2D counterparts, the size and character of the d(xz)/d(yz) Fermi surface components are essentially the same for different sample preparations. Irradiating SrTiO(3) in ultrahigh vacuum is one method observed so far to induce the "universal" surface metallic state. We reveal that during this process, changes in the oxygen valence band spectral weight that coincide with the emergence of surface conductivity are disproportionate to any change in the total intensity of the O 1s core level spectrum. This signifies that the formation of the metallic surface goes beyond a straightforward chemical doping scenario and occurs in conjunction with profound changes in the initial states and/or spatial distribution of near-E(F) electrons in the surface region.