Histological differences between lumbar and tail intervertebral discs in mice.

Both the lumbar and tail intervertebral discs (IVD) of mice serve as models for the pathogenesis and histologic progression of degenerative disc disease. Recent studies in mature mice, however, demonstrate that the mechanics and physical attributes of lumbar and tail IVD-endplate (EP)-interfaces are strikingly different. We hypothesized that these structural disparities are associated with differences in the composition and organization of soft tissue elements that influence the biomechanical properties of the spine. Lumbar and tail vertebral segments and discs were collected from the same C57BL/6N and C57BL/6JRj mice, respectively for histological comparison of coronal sections at the ages of 4 weeks (weaned, both strains, C57BL/6N: n = 7; C57BL/6JRj: n = 4), three (mature, C57BL/6N: n = 7; C57BL/6JRj: n = 4), twelve (middle aged, C57BL/6JRj only: n = 3) and eighteen (old, C57BL/6JRj only: n = 3) months old. The histology of lumbar and tail IVD-EP-interfaces of mature mice differed markedly. The lumbar IVD-EP-interphase was characterized by a broad cartilaginous EP, while the tail IVD-EP-interphase comprised a thin layer of cartilage cells adjacent to a broad bony layer abutting the vertebral growth plate. Furthermore, the composition of the nuclei pulposi (NP) of lumbar and tail IVD in mature mice differed greatly. Lumbar NP consisted of a compact cluster of mainly large, uni-vacuolated cells centered in an amorphous matrix, while tail NP were composed of a loose aggregate of vacuolated and non-vacuolated cells. The anuli fibrosi also differed, with more abundant and sharply defined lamellae in tail compared to lumbar discs. The observed histological differences in the EP were even most prominent in weaned mice but were still discernible in middle-aged and old mice. An appreciation of the histological differences between lumbar and tail IVD components in mice, including nucleus pulposus, annulus fibrosus, and endplates, is essential to our understanding of spinal biomechanics in these animals and should inform the design and interpretation of future IVD-studies.

Topography and evidence of a separate "fascia plate" for the femoral nerve inside the iliopsoas - A dorsal approach.

The femoral nerve stretch test is an essential part of clinical neurological examinations. This test is performed alongside Magnetic Resonance Imaging (MRI) to determine if there is any evidence of nerve root irritation, usually as a consequence of disc prolapse. The test occasionally gives false positive results. Why such false positives can occur, is subject to continued research, however, no obvious reason has yet emerged. We hypothesize that connectives of the femoral nerve may explain such a phenomenon. To see these connectives, we approached the femoral nerve from dorsal in 12 cases. With the use of ink injection into the subparaneural compartment of the femoral nerve and dissections, a thin transparent structure can clearly be seen that is separate from the epineurium, perineurium, and a paraneural sheath. A continuation of the paraneural sheath produces a fascia plate approximately 1.5 cm in width and with a thickness of around 3 mm, which not only circumnavigates the nerve but projects into the surrounding tissues. Our qualitative observations show that not only does this femoral nerve fascia plate exists, but it also contains nerves and vessels. Furthermore, we show that the femoral nerve is connected to the myofascial complex of the iliopsoas, and in a separate fascia plate from the iliopsoas fascia. This plate is a hitherto neglected connective which extends as far as the spinal dura mater. Evidence from our plastinates and histological sections suggests that when tension is applied to the femoral nerve during the femoral nerve stretch test, tension is also applied to the femoral nerve fascia plate. The femoral nerve fascia plate could be a specific factor that contributes to pain resulting in a false positive femoral nerve stretch test.

Volumetric measurements of paranasal sinuses and examination of sinonasal communication in healthy Shetland ponies: anatomical and morphometric characteristics using computed tomography.

BACKGROUND: Despite clinical importance and frequent occurrence of sinus disease, little is known about the size of paranasal sinuses and their communication in ponies and small horses. To examine the shape and volume of the paranasal sinuses and evaluate the sinonasal communication, three-dimensional (3D) reconstructions of computed tomography (CT) datasets of 12 healthy adult Shetland ponies were performed and analysed. Linear measurements of head length and width were taken. Using semi-automatic segmentation, 3D-models of all sinus compartments were created. Volumetric measurement of the seven sinus compartments were conducted and statistical analysis was performed. Sinus volumes were compared between the left and right sinuses and the relation to age and head size was evaluated. RESULTS: Structure and shape of the paranasal sinus system in Shetland ponies was similar to that of large horses. All seven sinus compartments on each side of the head were identified (rostral maxillary sinus, ventral conchal sinus, caudal maxillary sinus, dorsal conchal sinus, middle conchal sinus, frontal sinus, sphenopalatine sinus). The existence of a bilateral cranial and a caudal system formed by a maxillary septum was visible in all 12 individuals. The volumetric sizes of the left and right sinuses did not differ significantly (p > 0.05). A positive correlation between the size of the paranasal sinuses and the head length was shown. A relation between sinus volumes and age could not be proved in adult ponies aged > six years. Communication between single sinus compartments was identified. Furthermore, communication with the nasal cavity over the nasomaxillary aperture (Apertura nasomaxillaris) and a common sinonasal channel (Canalis sinunasalis communis) as well as its splitting up into a rostral and a caudolateral channel could be seen. Examination of the sinonasal communication was challenging and only a descriptive evaluation was possible. CONCLUSIONS: Our findings concerning the size, shape and volumetric dimensions of Shetland pony CT images could help improve CT interpretation of abnormal clinical cases as well as aiding clinicians to develop and select appropriate instruments for medical inspection and treatments.

Advances toward fully automated in vivo assessment of oral epithelial dysplasia by nuclear endomicroscopy-A pilot study.

BACKGROUND: Uncertainties in detection of oral epithelial dysplasia (OED) frequently result from sampling error especially in inflammatory oral lesions. Endomicroscopy allows non-invasive, "en face" imaging of upper oral epithelium, but parameters of OED are unknown. METHODS: Mucosal nuclei were imaged in 34 toluidine blue-stained oral lesions with a commercial endomicroscopy. Histopathological diagnosis showed four biopsies in "dys-/neoplastic," 23 in "inflammatory," and seven in "others" disease groups. Strength of different assessment strategies of nuclear scoring, nuclear count, and automated nuclear analysis were measured by area under ROC curve (AUC) to identify histopathological "dys-/neoplastic" group. Nuclear objects from automated image analysis were visually corrected. RESULTS: Best-performing parameters of nuclear-to-image ratios were the count of large nuclei (AUC=0.986) and 6-nearest neighborhood relation (AUC=0.896), and best parameters of nuclear polymorphism were the count of atypical nuclei (AUC=0.996) and compactness of nuclei (AUC=0.922). Excluding low-grade OED, nuclear scoring and count reached 100% sensitivity and 98% specificity for detection of dys-/neoplastic lesions. In automated analysis, combination of parameters enhanced diagnostic strength. Sensitivity of 100% and specificity of 87% were seen for distances of 6-nearest neighbors and aspect ratios even in uncorrected objects. Correction improved measures of nuclear polymorphism only. The hue of background color was stronger than nuclear density (AUC=0.779 vs 0.687) to detect dys-/neoplastic group indicating that macroscopic aspect is biased. CONCLUSIONS: Nuclear-to-image ratios are applicable for automated optical in vivo diagnostics for oral potentially malignant disorders. Nuclear endomicroscopy may promote non-invasive, early detection of dys-/neoplastic lesions by reducing sampling error.

Effortful control as a dimension of temperament is negatively associated with prefrontal serotonin transporter availability in obese and non-obese individuals.

There is evidence that temperamental factors are associated with obesity; however, the biological mechanism of such association remains elusive. We aimed to investigate a possible association between serotonin transmission and regulative temperament in obese and non-obese individuals by using positron emission tomography (PET) imaging of serotonin transporters (SERT) and the Adult Temperament Questionnaire. Twenty-nine obese individuals with body mass index (BMI) ≥ 35 kg/m2 and 13 non-obese controls (BMI < 30 kg/m2 ) underwent PET with [11 C]-labeled DASB (highly selective for SERT) and self-completed the Effortful Control (EC) scale of the Adult Temperament Questionnaire-Short Form (ATQ). With the help of this questionnaire, we aimed to assess the capacity of self-regulation. Overall, for obese and non-obese individuals together, VOI-based (volume of interest) analysis showed significant negative correlations between SERT BPND and ATQ-EC AC (Activation Control) subscale in several brain regions (all r ≤ -0.47). Obese and non-obese individuals separated showed equally strong positive, but non-significant correlations. The analysis did not reveal any significant correlations of SERT availability and ATQ-EC IC (Inhibitory Control) or ATQ-EC AtC (Attentional Control) subscale within and between the two groups. The results indicate that regulative temperament - particularly the capacity to mitigate negatively toned impulses and to resist inappropriate avoidance behavior - might be associated with the prefrontal serotonergic system.

Central serotonin transporter availability in highly obese individuals compared with non-obese controls: A [(11)C] DASB positron emission tomography study.

PURPOSE: The role of the central serotonin (5-hydroxytryptamine, 5-HT) system in feeding has been extensively studied in animals with the 5-HT family of transporters (5-HTT) being identified as key molecules in the regulation of satiety and body weight. Aberrant 5-HT transmission has been implicated in the pathogenesis of human obesity by in vivo positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging techniques. However, results obtained thus far from studies of central 5-HTT availability have been inconsistent, which is thought to be brought about mainly by the low number of individuals with a high body mass index (BMI) previously used. The aim of this study was therefore to assess 5-HTT availability in the brains of highly obese otherwise healthy individuals compared with non-obese healthy controls. METHODS: We performed PET using the 5-HTT selective radiotracer [(11)C] DASB on 30 highly obese (BMI range between 35 and 55 kg/m(2)) and 15 age- and sex-matched non-obese volunteers (BMI range between 19 and 27 kg/m(2)) in a cross-sectional study design. The 5-HTT binding potential (BPND) was used as the outcome parameter. RESULTS: On a group level, there was no significant difference in 5-HTT BPND in various cortical and subcortical regions in individuals with the highest BMI compared with non-obese controls, while statistical models showed minor effects of age, sex, and the degree of depression on 5-HTT BPND. CONCLUSION: The overall finding of a lack of significantly altered 5-HTT availability together with its high variance in obese individuals justifies the investigation of individual behavioral responses to external and internal cues which may further define distinct phenotypes and subgroups in human obesity.

The median nerve´s system of connective tissue distal to the pronator teres to the carpal tunnel.

BACKGROUND: Connective tissue serves a role beyond mere spatial filling. Furthermore, there is increasing evidence that connective tissue plays an important role in the pathogenesis of conditions such as carpal tunnel syndrome (CTS). According to our hypothesis, the median nerve (MN) is surrounded by a system of connective tissue distal to the pronator teres and extending up to, and including, the carpal tunnel. METHODS: To visualize the connective tissue surrounding the median nerve, we dissected the forearms of 15 body donors from pronator teres to the carpal tunnel, created plastination slices stained with Periodic Acid-Schiff (PAS), and injected ink into the seen spaces. We verified our findings with a segmentational analysis of radiological data of 10 healthy individuals. RESULTS: We macroscopically describe the median nerve´s system of connective tissue (MC) distal to the pronator teres and up to and including the carpal tunnel. This system creates, connects, and separates spaces. At least from the pronator teres to the carpal tunnel it also creates subspaces from proximal to distal. For the MC, we established a mean cross-sectional area of 153.1 mm2 (SD=37.15) in the carpal tunnel. The median nerve consistently resides at the center of this MC, which further connects to flexor muscles of the forearm, and to the radius bone. In the carpal tunnel, the MC creates subspaces inside. There, it also acts as the outermost internal layer enveloping flexor tendons, and the MN. DISCUSSION: The term MC does not negate but orders the existence of other "connectives", like subsynovial connective tissue, endo-, epi- or perineuria, epimysia, periostea, or peritendinea, to a hierarchy related to the median nerve. Diseases of the MN are common. Knowing the anatomy of the MC and how it relates to MN function may help clinicians recognize and understand conditions like CTS.

The adhesion GPCR GPR116/ADGRF5 has a dual function in pancreatic islets regulating somatostatin release and islet development.

Glucose homeostasis is maintained by hormones secreted from different cell types of the pancreatic islets and controlled by manifold input including signals mediated through G protein-coupled receptors (GPCRs). RNA-seq analyses revealed expression of numerous GPCRs in mouse and human pancreatic islets, among them Gpr116/Adgrf5. GPR116 is an adhesion GPCR mainly found in lung and required for surfactant secretion. Here, we demonstrate that GPR116 is involved in the somatostatin release from pancreatic delta cells using a whole-body as well as a cell-specific knock-out mouse model. Interestingly, the whole-body GPR116 deficiency causes further changes such as decreased beta-cell mass, lower number of small islets, and reduced pancreatic insulin content. Glucose homeostasis in global GPR116-deficient mice is maintained by counter-acting mechanisms modulating insulin degradation. Our data highlight an important function of GPR116 in controlling glucose homeostasis.

[Ultrasonographic findings of the stomach in warmblood horses at different filling states]. / Die sonografische Darstellung des Magens beim Warmblutpferd bei unterschiedlichen Füllungszuständen.

SUBJECT AND AIM: The aim of the study was to clarify to what extent the sonographic representation of the stomach changes depending on its filling state. MATERIAL AND METHODS: In a prospective controlled study, warmblood horses presented for gastroscopy were assessed sonographically. The examinations took place when the horses were fed normally (measurement 1), after 12 hours of food deprivation (measurement 2), after insufflation of air during gastroscopy (measurement 3) and after removal of air from the stomach at the end of the gastroscopy (measurement 4). The following objective parameters were recorded: Number of intercostal spaces (craniocaudal extension) and determination in which intercostal spaces the stomach could be visualized sonographically, maximum dorsal extension of the stomach, distance between skin and stomach wall. RESULTS: The median number of intercostal spaces in which the stomach could be visualized sonographically was 7.5 (IQR 3.75), 1.0 (IQR 1.0), 7.0 (IQR 2.0) and 2.0 (IQR 1.0) for measurements 1, 2, 3 (n=32) and 4 (n=15), respectively. The differences were significant between measurements 1 and 2 and between measurements 2 and 3. There was no significant difference between measurements 1 and 3. After 12 hours of food deprivation, the stomach size measured by the number of intercostal spaces visualizing the stomach was reduced by 75%. The maximum dorsal expansion of the stomach for measurements 1, 2, 3 (n=32) and 4 (n=15) was a median of 38 cm (IQR 15.25), 13 cm (IQR 6.75), 43 cm (IQR 7.00) and 21 cm (IQR 8.00), respectively. The differences were significant between measurements 1 and 2 and between 2 and 3. Concerning the distance between skin and stomach wall, the following medians were determined for measurements 1, 2, 3 (n=32) and 4 (n=15): 5.8 cm (IQR 2.27), 4.05 cm (IQR 3.05), 4.8 cm (IQR 1.48) and 5.9 cm (IQR 2.90). The only statistically significant difference was observed between measurements 1 and 3. CONCLUSIONS AND CLINICAL RELEVANCE: The sonographic appearance of the stomach changes according to the state of filling. Parameters that are readily determined sonographically are the craniocaudal and maximum dorsal extension as well as the distance between the skin and the stomach wall.

Approaches to standardising the magnetic resonance image analysis of equine tendon lesions.

Background: Low-field magnetic resonance imaging (MRI) has gained increasing importance to monitor equine tendon lesions. Comparing results between studies and cases is hampered, because image analysis approaches vary strongly. This study aimed to improve reliability, comparability and time efficiency of quantitative MRI image analysis. Methods: Induced tendon lesions were studied over a 24-week period with 10 follow-up MRI examinations. Signal intensities (SIs) of tendons, tendon lesions, cortical bone and background, as well as lesion cross-sectional areas (CSAs) were measured. Lesion SI standardisation with different formulas was evaluated, using histological findings as reference. Different types of region of interest (ROI) for lesion SI measurement were compared. Lesion CSA measurement at different levels was evaluated, using the calculated total lesion volume as reference. Subjective lesion identification and manual CSA and SI measurements were compared to an automated, algorithm-based approach. Results: Lesion SI standardised using a quotient of lesion and background or cortical bone SI, correlated best with histologically determined lesion severity. Lesion SI in circular ROIs correlated strongly with lesion SI in free-hand whole-lesion ROIs. The level of the maximum lesion CSA shifted over time; the CSA maximum correlated strongly with lesion volume. In sequences with short acquisition time, algorithm-based automated lesion detection showed almost perfect agreement with subjective lesion identification. Automated measurement of CSA and SI was also feasible, with stronger correlation and better agreement with the manually obtained data for the SI than for the CSA. Conclusion: Our study may provide guidance for MRI image analysis of tendon healing. Reliable image analysis can be performed time-efficiently, particularly regarding lesion SI quantification.

Accuracy Analysis of Computer-Assisted and Guided Dental Implantology by Comparing 3D Planning Data and Actual Implant Placement in a Mandibular Training Model: A Monocentric Comparison between Dental Students and Trained Implantologists.

The aim of this study was to investigate how precisely implantation can be realized by participants on a phantom head according to preliminary planning. Of particular interest here was the influence of participants' previous knowledge and surgical experience on the precision of the implant placement. The placed implants were scanned using an intraoral scanner, saved as STL files, and superimposed with the 3D-planned implant placement. Deviations from the planning were indicated in millimeters and degrees. We were able to show that on average, the deviations from computer-assisted 3D planning were less than 1 mm for implantologists, and the students also did not deviate more than 1.78 mm on average from 3D planning. This study shows that guided implantology provides predictable and reproducible results in dental implantology. Incorrect positioning, injuries to anatomical structures, and implant positions that cannot be prosthetically restored can thus be avoided.

Dental Root Injuries Caused by Osteosynthesis Screws in Orthognathic Surgery-Comparison of Conventional Osteosynthesis and Osteosynthesis by CAD/CAM Drill Guides and Patient-Specific Implants.

BACKGROUND/AIM: The primary aim was to evaluate the prevalence and localisation of dental injuries caused by osteosynthesis screws during orthognathic surgery, comparing two different CAD/CAM planning/surgical approaches through retrospective evaluation of post-operative computed tomography. MATERIAL AND METHODS: This study considered all patients who underwent orthognathic surgery from 2010-2019. The examination for dental root injuries between conventional osteosynthesis (Maxilla conventional cohort) and osteosynthesis with patient-specific implant (Maxilla PSI cohort) was performed by evaluating the post-operative CT scans. RESULTS: A total of 126 patients were included in the study. Among the 61 patients of the Maxilla conventional cohort, 10 dental root injuries in 8 patients (13.1%) were detected in the post-operative CT scan, representing 1.5% (n = 10/651) of the osteosynthesis screws inserted in proximity of the alveolar crest. No dental injury occurred following osteosynthesis in the 65 patients of the Maxillary PSI cohort (n = 0/773 screws) (p < 0.001). During a mean follow-up period of 13 months after primary surgery, none of the injured teeth showed evidence of periapical alterations and no endodontic treatments were necessary. CONCLUSIONS: Maxillary positioning using CAD/CAM-fabricated drill/osteotomy guide and osteosynthesis with PSI can significantly reduce the risk for dental injury compared to the conventional procedure. However, the clinical significance of the detected dental injuries was rather minor.

Comparison of Anatomical Preformed Titanium Implants and Patient-Specific CAD/CAM Implants in the Primary Reconstruction of Isolated Orbital Fractures-A Retrospective Study.

BACKGROUND/AIM: Reconstruction of the fractured orbit remains a challenge. The aim of this study was to compare anatomical preformed titanium orbital implants with patient-specific CAD/CAM implants for precision and intraoperative applicability. MATERIAL AND METHODS: A total of 75 orbital reconstructions from 2012 to 2022 were retrospectively assessed for their precision of implant position and intra- and postoperative revision rates. For this purpose, the implant position after digital orbital reconstruction was checked for deviations by mirroring the healthy orbit at 5 defined points, and the medical records of the patients were checked for revisions. RESULTS: The evaluation of the 45 anatomical preformed orbital implant cases showed significantly higher deviations and an implant inaccuracy of 66.6% than the 30 CAD/CAM cases with only 10% inaccuracy. In particular, the CAD/CAM implants were significantly more precise in medial and posterior positioning. In addition, the intraoperative revision rates of 26.6% vs. 11% after 3D intraoperative imaging and the postoperative revision rates of 13% vs. 0 for the anatomical preformed implants were significantly higher than for patient-specific implants. CONCLUSION: We conclude that patient-specific CAD/CAM orbital implants are highly suitable for primary orbital reconstruction. These seem to be preferable to anatomical preformed implants in terms of precision and revision rates.

Reduced urine volume and changed renal sphingolipid metabolism in P2ry14-deficient mice.

The UDP-glucose receptor P2RY14, a rhodopsin-like G protein-coupled receptor (GPCR), was previously described as receptor expressed in A-intercalated cells of the mouse kidney. Additionally, we found P2RY14 is abundantly expressed in mouse renal collecting duct principal cells of the papilla and epithelial cells lining the renal papilla. To better understand its physiological function in kidney, we took advantage of a P2ry14 reporter and gene-deficient (KO) mouse strain. Morphometric studies showed that the receptor function contributes to kidney morphology. KO mice had a broader cortex relative to the total kidney area than wild-type (WT) mice. In contrast, the area of the outer stripe of the outer medulla was larger in WT compared to KO mice. Transcriptome comparison of the papilla region of WT and KO mice revealed differences in the gene expression of extracellular matrix proteins (e.g., decorin, fibulin-1, fibulin-7) and proteins involved in sphingolipid metabolism (e.g., small subunit b of the serine palmitoyltransferase) and other related GPCRs (e.g., GPR171). Using mass spectrometry, changes in the sphingolipid composition (e.g., chain length) were detected in the renal papilla of KO mice. At the functional level, we found that KO mice had a reduced urine volume but an unchanged glomerular filtration rate under normal chow and salt diets. Our study revealed P2ry14 as a functionally important GPCR in collecting duct principal cells and cells lining the renal papilla and the possible involvement of P2ry14 in nephroprotection by regulation of decorin.

Taxane-Induced Neuropathy and Its Ocular Effects-A Longitudinal Follow-up Study in Breast Cancer Patients.

A common severe neurotoxic side effect of breast cancer (BC) therapy is chemotherapy-induced peripheral neuropathy (CIPN) and intervention is highly needed for the detection, prevention, and treatment of CIPN at an early stage. As the eye is susceptible to neurotoxic stimuli, the present study aims to determine whether CIPN signs in paclitaxel-treated BC patients correlate with ocular changes by applying advanced non-invasive biophotonic in vivo imaging. Patients (n = 14, 10 controls) underwent monitoring sessions after diagnosis, during, and after therapy (T0-T3). Monitoring sessions included general anamnesis, assessment of their quality of life, neurological scores, ophthalmological status, macular optical coherence tomography (OCT), and imaging of their subbasal nerve plexus (SNP) by large-area confocal laser-scanning microscopy (CLSM). At T0, no significant differences were detected between patients and controls. During treatment, patients' scores significantly changed while the greatest differences were found between T0 and T3. None of the patients developed severe CIPN but retinal thickenings could be detected. CLSM revealed large SNP mosaics with identical areas while corneal nerves remained stable. The study represents the first longitudinal study combining oncological examinations with advanced biophotonic imaging techniques, demonstrating a powerful tool for the objective assessment of the severity of neurotoxic events with ocular structures acting as potential biomarkers.

Comparison of different fabrication techniques for human adipose tissue engineering in severe combined immunodeficient mice.

Adipose tissue engineering has been advocated for soft-tissue augmentation and for the treatment of soft tissue defects. The efficacy in terms of persistence of the engineered fat is, however, not yet understood and could depend on the nature of fabrication and application. The high metabolic demand of adipose tissue also points to the problem of vascularization. Endothelial cell (EC) cotransplantation could be a solution. Human adipose tissue-derived stromal cells were seeded on collagen microcarriers and submitted to adipogenic differentiation ("microparticles"). In a first run of experiments, these microparticles were implanted under the skin of severe combined immunodeficient (SCID) mice (n = 45) with and without the addition of human umbilical vein ECs (HUVECs). A group of carriers without any cells served as control. In a second run, adipose tissue constructs were fabricated by embedding microparticles in fibrin matrix with and without the addition of HUVEC, and were also implanted in SCID mice (n = 30). The mice were sacrificed after 12 days, 4 weeks, and 4 months. Mature adipose tissue, fibrous tissue, and acellular regions were quantified on whole-specimen histological sections. The implantation of microparticles showed a better sustainment of tissue volume and a higher degree of mature adipose tissue compared with adipose tissue constructs. Immunohistology proved obviously perfused human tissue-engineered vessels. There was a limited but not significant advantage in EC cotransplantation after 4 weeks in terms of tissue volume. In groups with EC cotransplantation, there were significantly fewer acellular/necrotic areas after 4 weeks and 4 months. In conclusion, the size of the implanted tissue equivalents is a crucial parameter, affecting volume maintenance and the gain of mature adipose tissue. EC cotransplantation leads to functional stable vascular networks connecting in part to the host vasculature and contributing to tissue perfusion; however, the long-term benefit depends on additional basic conditions that need further research.

Equine skeletal scintigraphy: Comparing normal bone-to-soft tissue ratio 2 and 4 hours after injection with either hydroxymethylene diphosphonate or methylene diphosphonate.

BACKGROUND: In equine skeletal scintigraphy, there is no information about the possible influence of different phosphonate compounds on image quality. METHODS: This prospective randomised study determined bone uptake changes and image quality for hydroxymethylene diphosphonate (HDP) and methylene diphosphonate (MDP) in equine patients at different time points. Scintigraphic images of the radius and the tibia of 20 horses were acquired at 2 and 4 hours after injection of either technetium-labelled HDP or MDP. Three regions of interest were identified-in the bone diaphysis, adjacent soft tissue and background area-to determine the normal bone-to-soft tissue ratio (BSR). Qualitative analysis was performed using a modified scoring system. RESULTS: In terms of BSR and count rates, HDP showed a slightly better incorporation into bone compared to MDP, but significant differences were only detected for count rates at 4 hours after injection (p = 0.048). The radiopharmaceutical used did not influence qualitative image scoring, which was correlated with the BSR (ρ = 0.49; p ≤ 0.001). CONCLUSION: The choice of HDP or MDP for equine skeletal scintigraphy does not seem to substantially affect BSR and qualitative image scoring. Further studies with a larger sample size, including the evaluation of lesion detection ability for both bone-seeking agents, are needed.

[Venous catheters in horses - early ultrasonographic venous abnormalities and evidence of biofilms]. / Ultrasonografische Früherkennung von Venenveränderungen sowie der Nachweis von Biofilmen auf Venenverweilkathetern beim Pferd.

OBJECTIVE: Complications associated with indwelling intravenous catheters vary from minor to severe. Changes in tissue architecture and vein structure may be detectable prior to clinical alterations. The aim of the study was to characterize and compare changes in a catheterized vein and surrounding tissue by clinical and ultrasonographic examination. Microbiological infestation of catheter specimens was assessed. MATERIAL AND METHODS: In this prospective, observational, clinical study 55 horses with an indwelling intravenous catheter have been included. Subsequent to catheter placement, vein and surrounding tissue were daily examined clinically and by ultrasonographic examination at predetermined localizations. After sterile removal of the catheters, specimens underwent microbiological testing and scanning electron microscopy. Obtained data were analyzed via descriptive statistics. Thickness of the venous wall was compared at predetermined localizations and time points for several parameters with the help of non-parametric tests (level of significance at p < 0.05, post-hoc Bonferroni correction). RESULTS: Overall, in 41.8 % of the horses transient alterations (swelling) of the surrounding tissue occurred during catheterization. Median catheterization was 69.5 hours (19 hour-10 days). With ultrasonography, venous valves and collateral vessels could be detected reliably. Significant alterations in wall thickness during catheterization were associated with various factors (location site [p ≤ 0.001], season [p = 0.006], anesthesia [p ≤ 0.001]).Microbiological analysis revealed a positive result in 23.5 %, 12 of the 51 samples; raster electron microscopy showed presence of bacteria in 25.0 %, 4 of the 16 investigated catheter samples. CONCLUSION AND CLINICAL RELEVANCE: Local tissue changes at the insertion site of the catheter are commonly associated with catheterization, and are easily detectable with ultrasonography. Despite the easy performance in a clinical setting, the benefit of routine ultrasonographic monitoring of catheterized veins might be questionable with regard to early identification and prediction of catheter-associated venous disease. Bacteria might be detectable morphologically on the catheter but frequently lack a positive result from standard bacterial cultivation.

Droplet Degeneration of Hippocampal and Cortical Neurons Signifies the Beginning of Neuritic Plaque Formation.

BACKGROUND: Neuritic plaques contain neural and microglial elements, and amyloid-ß protein (Aß), but their pathogenesis remains unknown. OBJECTIVE: Elucidate neuritic plaque pathogenesis. METHODS: Histochemical visualization of hyperphosphorylated-tau positive (p-tau+) structures, microglia, Aß, and iron. RESULTS: Disintegration of large projection neurons in human hippocampus and neocortex presents as droplet degeneration: pretangle neurons break up into spheres of numerous p-tau+ droplets of various sizes, which marks the beginning of neuritic plaques. These droplet spheres develop in the absence of colocalized Aß deposits but once formed become encased in diffuse Aß with great specificity. In contrast, neurofibrillary tangles often do not colocalize with Aß. Double-labelling for p-tau and microglia showed a lack of microglial activation or phagocytosis of p-tau+ degeneration droplets but revealed massive upregulation of ferritin in microglia suggesting presence of high levels of free iron. Perl's Prussian blue produced positive staining of microglia, droplet spheres, and Aß plaque cores supporting the suggestion that droplet degeneration of pretangle neurons in the hippocampus and cortex represents ferroptosis, which is accompanied by the release of neuronal iron extracellularly. CONCLUSION: Age-related iron accumulation and ferroptosis in the CNS likely trigger at least two endogenous mechanisms of neuroprotective iron sequestration and chelation, microglial ferritin expression and Aß deposition, respectively, both contributing to the formation of neuritic plaques. Since neurofibrillary tangles and Aß deposits colocalize infrequently, tangle formation likely does not involve release of neuronal iron extracellularly. In human brain, targeted deposition of Aß occurs specifically in response to ongoing ferroptotic droplet degeneration thereby producing neuritic plaques.

3T MRI characteristics of the palatine tonsil in brachycephalic dogs.

BACKGROUND: Investigation of the MRI characteristics of the palatine tonsil in brachycephalic dogs in 3T high-field system. METHODS: Eighty-five brachycephalic dogs and 37 normocephalic dogs were divided into five groups: group 1 French bulldogs (FBs) with neurological clinical signs (n = 37), group 2 FBs with brachycephalic obstructive airway syndrome (BOAS) (n = 22), group 3 pugs with neurological clinical signs (n = 17), group 4 pugs with BOAS (n = 9) and group 5 normocephalic dogs (n = 37). Cross-sectional area and volume measurements were performed, and tonsillar margination and contour, shape, signal intensity and homogeneity/heterogeneity of the palatine tonsils were evaluated and compared. RESULTS: Cross-sectional area and volume measurements of the tonsils showed no significant differences between brachycephalic and normocephalic dogs with the exception of the dogs of group 2 (FB BOAS), which showed relatively high volume and large cross-sectional area in comparison to other groups. In 87% of the brachycephalic animals, the tonsils were well defined. A smooth contour was detectable in 91.8% and a rounded shape in 94.7% of brachycephalic dogs. Signal intensity was assessed as hyperintense in relation to the musculature and iso- to hyperintense to the soft palate. Heterogeneous appearance was described in 86.9% of the brachycephalic animals. CONCLUSIONS: The MRI characteristics of the tonsils of brachycephalic dogs do not differ considerably from those of normocephalic dogs. In FBs with distinct clinical signs of obstructive airway syndrome, increase in cross-sectional area and volume of the tonsils was detected.