The impact of 18F-FDOPA-PET/MRI image fusion in detecting liver metastasis in patients with neuroendocrine tumors of the gastrointestinal tract.

BACKGROUND: This study assesses the value of image fusion using 18F-fluoro-L-DOPA (18F-DOPA) positron emission tomography (PET) and magnetic resonance imaging (MRI) for examining patients with neuroendocrine tumors (NETs) and a suspicion of metastasis of the liver. METHODS: Eleven patients (five women and six men aged between 20 and 81, with a mean age of 54.6 years) were included in the study. All patients underwent whole-body 18F-DOPA PET examinations and contrast-enhanced MRI with diffusion-weighted sequences (DWS). Image fusion was performed using a semiautomatic voxel-based algorithm. Images obtained using PET and MRI were assessed separately. Side-by-side evaluations of fused PET/MRI images were also performed. RESULTS: In total, 55 liver lesions (52 liver metastases and 3 benign lesions) were detected in the 11 patients. Sensitivity detection for liver lesions was higher when using PET/CT than when using contrast-enhanced MRI without DWSs and lower than using MRI with DWSs. The sensitivity of PET/MRI image fusion in the detection of liver metastasis was significantly higher than that of MRI with DWSs (P < 0.05). CONCLUSION: Images of the liver obtained using PET and MRI in patients with NETs exhibited characteristic features. These findings suggest that an appropriate combination of available imaging modalities can optimize patient evaluations.

Biomechanical evaluation of two methods of fixation of a flexor hallucis longus tendon graft.

Aims: The traditional transosseus flexor hallucis longus (FHL) tendon transfer for patients with Achilles tendinopathy requires two incisions to harvest a long tendon graft. The use of a bio-tenodesis screw enables a short graft to be used and is less invasive, but lacks supporting evidence about its biomechanical behaviour. We aimed, in this study, to compare the strength of the traditional transosseus tendon-to-tendon fixation with tendon-to-bone fixation using a tenodesis screw, in cyclical loading and ultimate load testing. Materials and Methods: Tendon grafts were undertaken in 24 paired lower-leg specimens and randomly assigned in two groups using fixation with a transosseus suture (suture group) or a tenodesis screw (screw group). The biomechanical behaviour was evaluated using cyclical and ultimate loading tests. The Student's t-test was performed to assess statistically significant differences in bone mineral density (BMD), displacement, the slope of the load-displacement curves, and load to failure. Results: The screw group showed less displacement (loosening) during cyclical loading, which was significant during 300, 500, 600, 700, 800, 900, and 1000 cycles (p < 0.05: other cycles: 0.079 < p < 0.402). Compared with the suture group, the screw group had higher mean ultimate load values (133.6 N, sd 73.5 vs 110.1 N, sd 46.2; p = 0.416). Conclusion: Fixation of the FHL tendon with a tenodesis screw enables a less invasive procedure to be undertaken and shows similar biomechanical behaviour and primary strength compared with fixation using a transosseus suture. Cite this article: Bone Joint J 2018;100-B:1175-81.

Novel familial mutation of LRP5 causing high bone mass: Genetic analysis, clinical presentation, and characterization of bone matrix mineralization.

The Wnt signalling pathway is a critical regulator of bone mass and quality. Several heterozygous mutations in the LRP5 gene, a Wnt co-receptor, causing high bone mass (LRP5-HBM) have been described to date. The pathogenic mechanism is thought to be a gain-of-function caused by impaired inhibition of the canonical Wnt signalling pathway, thereby leading to increased bone formation. We report the cases of two affected family members, a 53-year-old mother and her 23-year-old daughter, with high bone mass (T-scores mother: lumbar spine 11.4, femoral neck 10.5; T-scores daughter: lumbar spine 5.4, femoral neck 8.7), increased calvarial thickness, and thickened cortices of the long bones but no history of fractures. Whereas the mother did not show any indications of the mutation, the daughter suffered from congenital hearing impairment resulting in cochlear implantation, recurrent facial palsy, and migraine. In addition, she had stenosis of the foramen magnum. In both individuals, we detected a novel heterozygous duplication of six basepairs in the LRP5 gene, resulting in an insertion of two amino acids, very likely associated with a gain-of-function. When the daughter had part of the occipital bone surgically removed, the bone sample was used for the visualization of bone lamellar structure and bone cells as well as the measurement of bone mineralization density distribution (BMDD). The bone sample revealed two distinctly different regions: an intra-cortical region with osteonal remodeling, typical osteonal lamellar orientation, associated with relatively higher heterogeneity of bone matrix mineralization, and another periosteal region devoid of bone remodeling, with parallel bone lamellae and lower heterogeneity of mineralization. In conclusion, we present data on bone tissue and material level from an LRP5-HBM patient with a novel mutation in the LRP5 gene. Our findings indicate normal morphology of osteoclasts and osteoblasts as well as normal mineralization in skull bone in LRP5-HBM.

The Characteristics of an Ovine Lymphoid Cell-Line sensitive to Vaccinal Infectious Bursal Disease Virus Strain.

Infectious bursal disease (IBD), also known as Gumboro disease, is a globally well-known disease with a significant socio-economic effect. For control of IBD, several commercial egg- and cell-based vaccines are prepared. The cell-based IBD vaccines are significantly cost-effective; however, it is essential to confirm their safety and efficacy. The main cell line used to product the cell-based IBD vaccines, is a primary chicken embryo fibroblast (CEF). Nevertheless, manipulation of CEF is extremely challenging and time-consuming. This study aimed to characterize a sensitive suspension cell culture from ovine lymphoid, according to WHO technical report series; No. 978, Annex III. This authentication covered the growth curves, sensitivity, stability, karyotyping and identifying the adventitious agents. This cell line passed all defined tests and was considered as a suitable one for IBD vaccine preparation in a large scale.

Comparison of Broström technique, suture anchor repair, and tape augmentation for reconstruction of the anterior talofibular ligament.

PURPOSE: Recently, tape augmentation for Broström repair has been introduced in order to improve the primary stability of the reconstructed anterior talofibular ligament (ATFL). The biomechanical effect of tape augmentation suture anchor (SA) repair is not known yet. The aim of the present study was to compare construct stability of the traditional Broström (TB) repair compared with a stand alone SA repair (SutureTak, Arthrex) and SA repair combined with tape augmentation (InternalBrace, Arthrex) internal brace (IB) of the ATFL. METHODS: Eighteen fresh-frozen human anatomic lower leg specimens were randomly assigned to three different groups: TB group, SA group, and IB augmentation group. In vivo torsion conditions in ankle sprain were carried out quasi-statically (0.5°/s). Torque (Nm) required to resist as well as the rotary displacement (°) of the load frame was recorded. Intergroup differences for age, bone mineral density (BMD), angle at failure, and torque at failure were analysed using ANOVA. RESULTS: In the TB group, ATFL reconstruction failed at an angle of 24.1°, in the SA group failure occurred at 35.5°, and in the IB group it failed at 46.9° (p = 0.02). Torque at failure reached 5.7 Nm for the TB repair, 8.0 Nm for the SA repair, and 11.2 Nm for the IB group (p = 0.04). There was no correlation between angle at ATFL failure, torque at failure, and BMD for the SA or IB groups. CONCLUSION: The present biomechanical study reveals statistically superior performance in terms of angle at failure as well as failure torque for the IB group compared to the other reconstruction methods. BMD did not influence the construct stability in the SA repair groups.

Screening markers of impaired glucose tolerance in the obese pediatric population.

BACKGROUND: With the epidemic of childhood obesity, it is crucial to devise a simple screening protocol to predict impaired glucose tolerance (IGT) or pre-diabetes. The oral glucose tolerance test (OGTT), which is the gold standard for the diagnosis of IGT, is impractical for screening purposes. This pilot study was designed to formulate a simple, sensitive algorithm to predict IGT using clinical and laboratory parameters. METHODS: Ethnicity, family history of diabetes, pubertal status, BMI z-score, blood pressure, lipids, hemoglobin A1c (HbA1c) and OGTT data were retrospectively collected from 209 overweight multi-ethnic subjects aged 3-21 years. Multivariate logistic regression was used to determine independent predictors of IGT. RESULTS: HbA1c was the only significant predictor of IGT (p = 0.001), whereas fasting glucose was not. A cut-off of 5.5% had the best combined sensitivity (85.7%) and specificity (56.9%) with an odds ratio of 7.9 of having IGT when HbA1c is > or =5.5%. The remaining clinical parameters were not significant predictors of IGT. CONCLUSION: While fasting blood glucose does not seem to be a predictor of IGT, we propose that HbA1c > or =5.5% can be used as a screening test to assess the risk of IGT and to determine who should undergo diagnostic OGTT. Large prospective studies validating our findings are warranted.

Hirsutism.

Hirsutism is defined as the excessive growth of terminal hair on the face and body of a female in a typical male pattern distribution. Hirsutism is a common clinical problem in women and the treatment depends on the cause of hirsutism. Untreated hirsutism can be associated with considerable loss of self-esteem and psychological morbidity. Hyperandrogenemia is the key trigger for excess hair growth. Polycystic ovary syndrome and idiopathic hirsutism are the most common cause of hirsutism. As with all medical problems, investigation begins with a careful history, examination and then investigation directed at the possible cause. A raised serum testosterone level of > 150 ng/dl (5.2 nmol/l) should prompt further investigations to exclude an underlying androgen-secreting tumour. The treatment of hirsutism is most effective using combination therapy, including lifestyle therapies, androgen suppression, peripheral androgen blockage and cosmetic treatments. Women should be warned not to expect improvement or at least 3-6 months after therapy is begun and lifelong therapy may be needed to prevent recurrence. The current review discusses definition, pathogenesis, differential diagnosis, diagnostic strategies, management, guidelines and the authors' recommendations about hirsutism.

Nerve regeneration using tubular scaffolds from biodegradable polyurethane.

INTRODUCTION: In severe nerve lesion, nerve defects and in brachial plexus reconstruction, autologous nerve grafting is the golden standard. Although, nerve grafting technique is the best available approach a major disadvantages exists: there is a limited source of autologous nerve grafts. This study presents data on the use of tubular scaffolds with uniaxial pore orientation from experimental biodegradable polyurethanes coated with fibrin sealant to regenerate a 8 mm resected segment of rat sciatic nerve. METHODS: Tubular scaffolds: prepared by extrusion of the polymer solution in DMF into water coagulation bath. The polymer used for the preparation of tubular scaffolds was a biodegradable polyurethane based on hexamethylene diisocyanate, poly(epsilon-caprolactone) and dianhydro-D-sorbitol. EXPERIMENTAL MODEL: Eighteen Sprague Dawley rats underwent mid-thigh sciatic nerve transection and were randomly assigned to two experimental groups with immediate repair: (1) tubular scaffold, (2) 180 degrees rotated sciatic nerve segment (control). Serial functional measurements (toe spread test, placing tests) were performed weekly from 3rd to 12th week after nerve repair. On week 12, electrophysiological assessment was performed. Sciatic nerve and scaffold/nerve grafts were harvested for histomorphometric analysis. Collagenic connective tissue, Schwann cells and axons were evaluated in the proximal nerve stump, the scaffold/nerve graft and the distal nerve stump. The implants have uniaxially-oriented pore structure with a pore size in the range of 2 micorm (the pore wall) and 75 x 700 microm (elongated pores in the implant lumen). The skin of the tubular implants was nonporous. Animals which underwent repair with tubular scaffolds of biodegradable polyurethanes coated with diluted fibrin sealant had no significant functional differences compared with the nerve graft group. Control group resulted in a trend-wise better electrophysiological recovery but did not show statistically significant differences. There was a higher level of collagenic connective tissue within the scaffold and within the distal nerve stump. Schwann cells migrated into the polyurethane scaffold. There was no statistical difference to the nerve graft group although Schwann cell counts were lower especially within the middle of the polyurethane scaffold. Axon counts showed a trend-wise decrease within the scaffold. CONCLUSION: These results suggest that biodegradable polyurethane tubular scaffolds coated with diluted fibrin sealant support peripheral nerve regeneration in a standard gap model in the rat up to 3 months. Three months after surgery no sign of degradation could be seen.

In peripheral nerve regeneration environment enriched with activity stimulating factors improves functional recovery.

Enriched environment stimulates brain plasticity processes after brain lesion. Less is known about the influence of enriched environment with activity stimulating factors as determinants of functional outcome after peripheral nerve repair. BDNF (brain-derived neurotrophic factor) plays a role in activity-dependent neuronal plasticity and changes in motor cortex in rats learning complex motor skills. Our study aimed to elucidate if enriched environment influences functional results after peripheral nerve repair. The results in this rat sciatic nerve transection and repair model showed that environment enriched with activity stimulating factors can improve functional results.

The effect of ketamine/xylazine anesthesia on sensory and motor evoked potentials in the rat.

STUDY DESIGN: Experimental laboratory investigation of the effect of anesthesia on evoked potentials in rats. OBJECTIVES: To define the optimal ketamine/xylazine anesthesia levels for the recording of different evoked potentials. SETTING: BioSurgery Preclinical Department, Baxter BioScience, Vienna, Austria. METHODS: Rats were implanted with cranial screws that allow stimulation and recording of evoked potentials. Somatosensory evoked potentials (SEPs), brainstem-derived motor evoked potentials (BMEPs) and corticomotor evoked potential (CMEPs) were recorded under different levels of anesthesia. The recorded signals were evaluated by measuring their latencies and amplitudes. The level of anesthesia was assessed by scoring the hind limb withdrawal reflex. RESULTS: All three signals showed a strong dependency on the level of anesthesia. The observed effects, however, differed between the three signals. SEP amplitudes and latencies declined as animals slowly transgressed from deep to light anesthesia. In contrast, BMEP amplitudes were larger and latencies shorter in light anesthesia than in deep anesthesia. CMEPs finally were hard to record under deep anesthesia, but were easily recorded in light anesthesia. BMEPs that were recorded during light anesthesia also showed a significant change in configuration that was coupled with a notable increase in the variability of its amplitudes. CONCLUSIONS: The level of ketamine/xylazine anesthesia affects evoked potentials and thus should be controlled during electrophysiological recording. Our results suggest that SEPs should be best recorded during deep anesthesia, while BMEPs and CMEPs are best recorded during intermediate and light anesthesia.