Circular polarization in the optical afterglow of GRB 121024A.

Gamma-ray bursts (GRBs) are most probably powered by collimated relativistic outflows (jets) from accreting black holes at cosmological distances. Bright afterglows are produced when the outflow collides with the ambient medium. Afterglow polarization directly probes the magnetic properties of the jet when measured minutes after the burst, and it probes the geometric properties of the jet and the ambient medium when measured hours to days after the burst. High values of optical polarization detected minutes after the burst of GRB 120308A indicate the presence of large-scale ordered magnetic fields originating from the central engine (the power source of the GRB). Theoretical models predict low degrees of linear polarization and no circular polarization at late times, when the energy in the original ejecta is quickly transferred to the ambient medium and propagates farther into the medium as a blast wave. Here we report the detection of circularly polarized light in the afterglow of GRB 121024A, measured 0.15 days after the burst. We show that the circular polarization is intrinsic to the afterglow and unlikely to be produced by dust scattering or plasma propagation effects. A possible explanation is to invoke anisotropic (rather than the commonly assumed isotropic) electron pitch-angle distributions, and we suggest that new models are required to produce the complex microphysics of realistic shocks in relativistic jets.

Radioablation of adrenal gland malignomas with interstitial high-dose-rate brachytherapy : Efficacy and outcome.

PURPOSE: To assess the efficacy, safety, and outcome of image-guided high-dose-rate (HDR) brachytherapy in patients with adrenal gland metastases (AGM). MATERIALS AND METHODS: From January 2007 to April 2014, 37 patients (7 female, 30 male; mean age 66.8 years, range 41.5-82.5 years) with AGM from different primary tumors were treated with CT-guided HDR interstitial brachytherapy (iBT). Primary endpoint was local tumor control (LTC). Secondary endpoints were time to untreatable progression (TTUP), time to progression (TTP), overall survival (OS), and safety. In a secondary analysis, risk factors with an influence on survival were identified. RESULTS: The median biological equivalent dose (BED) was 37.4 Gy. Mean LTC after 12 months was 88%; after 24 months this was 74%. According to CTCAE criteria, one grade 3 adverse event occurred. Median OS after first diagnosis of AGM was 18.3 months. Median OS, TTUP, and TTP after iBT treatment were 11.4, 6.6, and 3.5 months, respectively. Uni- and multivariate Cox regression analyses revealed significant influences of synchronous disease, tumor diameter, and the total number of lesions on OS or TTUP or both. CONCLUSION: Image-guided HDR-iBT is safe and effective. Treatment- and primary tumor-independent features influenced survival of patients with AGM after HDR-iBR treatment.

Friction properties of a new silk fibroin scaffold for meniscal replacement.

The menisci protect the articular cartilage by reducing contact pressure in the knee. To restore their function after injury, a new silk fibroin replacement scaffold was developed. To elucidate its tribological properties, friction of the implant was tested against cartilage and glass, where the latter is typically used in tribological cartilage studies. The silk scaffold exhibited a friction coefficient against cartilage of 0.056, which is higher than meniscus against cartilage but in range of the requirements for meniscal replacements. Further, meniscus friction against glass was lower than cartilage against glass, which correlated with the surface lubricin content. Concluding, the tribological properties of the new material suggest a possible long-term chondroprotective function. In contrast, glass always produced high, non-physiological friction coefficients.

[Unicentre Results in Surgery of Primary Hyperparathyroidism with Postoperative Long-Term Follow-Up and Value of Intraoperative Quick Parathormone Test]. / Unizentrische Ergebnisse der Chirurgie des primären Hyperparathyreoidismus mit postoperativer Langzeitbeobachtung sowie Rolle des intraoperativen Quick-Parathormon-Tests.

BACKGROUND: The increasing use of focussed parathyroidectomy is attributed to introduction of intraoperative parathyroid hormone measurement (ioPTH) and novel preoperative imaging techniques. This study assesses the early postoperative and long-term outcomes of surgery and the value of standardised ioPTH in patients undergoing surgery for primary hyperparathyroidism (pHPT). METHODS: From 01/01/1996 to 09/30/2011, all consecutive patients undergoing surgery for pHPT were documented. Data of this observational study were retrospectively evaluated. Patients were subdivided into 2 groups: A.) use of Quick Intraoperative Intact PTH Assay (n = 142; "ioPTH group") vs. B.) control group ("CG", n = 44). For clinical long-term follow-up, also pre- and postoperative signs, symptoms and findings of the initial 43 patients obtained during the first 4 years of the study were semiquantitatively compared. RESULTS: 186 consecutive operations for pHPT were performed - in particular, 73 sole parathyroidectomies; 113 combined thyroid and parathyroid resections. Mean operation time was 87 (SD ± 48) min for parathyroidectomy and 120 (SD ± 49) min for combined resections. A persisting hypercalcaemia was found in 16 patients (8.6%) while postoperative elevation of serum calcium and parathormone occurred in 7 patients (3.8%). Postoperative hypocalcaemia was present in 35 patients (18.8%). Differences between both groups regarding hypocalcaemia (p = 1.0), hypercalcaemia (p = 0.67), hyperparathyrinaemia (p = 0.12) and rate of reintervention (p = 0.055) were not significant. Thirty nine of the initial 43 patients reported one or more signs of pHPT (90.7%). Most frequent symptoms were nephrolithiasis (41.9%), back pain (51.2%), discomfort in the upper abdomen (41.9%), fatigue (41.9%) and general weakness (61.1%). Follow-up investigations (mean, 4.7 [range, 3.2-6.5] years) revealed that 65 % of patients reported improvement of general condition, 27% had no change and 8% reported deterioration. CONCLUSIONS: IoPTH is now standard in parathyroid surgery. Value of ioPTH correlates directly with selected centre-specific intraoperative criteria. The stricter the criteria the more reliable is the exclusion of multiglandular disease. Surgery for pHPT was performed with a very low complication rate. Through the long-term follow-up, nearly two thirds of patients benefited from the operation.

A gamma-ray burst at a redshift of z approximately 8.2.

Long-duration gamma-ray bursts (GRBs) are thought to result from the explosions of certain massive stars, and some are bright enough that they should be observable out to redshifts of z > 20 using current technology. Hitherto, the highest redshift measured for any object was z = 6.96, for a Lyman-alpha emitting galaxy. Here we report that GRB 090423 lies at a redshift of z approximately 8.2, implying that massive stars were being produced and dying as GRBs approximately 630 Myr after the Big Bang. The burst also pinpoints the location of its host galaxy.

Flares from a candidate Galactic magnetar suggest a missing link to dim isolated neutron stars.

Magnetars are young neutron stars with very strong magnetic fields of the order of 10(14)-10(15) G. They are detected in our Galaxy either as soft gamma-ray repeaters or anomalous X-ray pulsars. Soft gamma-ray repeaters are a rare type of gamma-ray transient sources that are occasionally detected as bursters in the high-energy sky. No optical counterpart to the gamma-ray flares or the quiescent source has yet been identified. Here we report multi-wavelength observations of a puzzling source, SWIFT J195509+261406. We detected more than 40 flaring episodes in the optical band over a time span of three days, and a faint infrared flare 11 days later, after which the source returned to quiescence. Our radio observations confirm a Galactic nature and establish a lower distance limit of approximately 3.7 kpc. We suggest that SWIFT J195509+261406 could be an isolated magnetar whose bursting activity has been detected at optical wavelengths, and for which the long-term X-ray emission is short-lived. In this case, a new manifestation of magnetar activity has been recorded and we can consider SWIFT J195509+261406 to be a link between the 'persistent' soft gamma-ray repeaters/anomalous X-ray pulsars and dim isolated neutron stars.

[Preventive bone mineral density measurement in postmenopausal women. Differentiation of treatment of recommendations Guidelines of the Umbrella Organization for Osteology ("Dachverband Osteologie")]. / Präventive Knochendichtemessung bei postmenopausalen Frauen. Differenzierung der Therapieempfehlungen der Leitlinien des Dachverbandes Osteologie (DVO).

BACKGROUND: Osteopenia (OP) or osteoporosis (OST) was diagnosed by bone densitometry (DXA) in postmenopausal women free of known skeletal disorders and without acute fracture. DVO guidelines were applied to define therapeutic indication. METHODS: The study included 94 women aged 59-81 years. Fracture or operation ≤12 months, malignant tumor, ovariectomy, and drugs such as cortisone, strontium, fluorides, bisphosphonates, SERMs, estrogens, and steroids were exclusion criteria. The lowest T-score at the spine, femoral neck, or total hip was decisive. The indication for therapy was determined by evaluating age, BMD, and other risk factors. RESULTS: Using the WHO criteria 22.3% (n=21) had normal BMD, 52.1% (n=49) had OP, and 25.6% (n=24) had OST. According to "Dachverband Osteologie" (DVO) guidelines, 28 women (29.8%) of the whole group needed therapy. Of the 28 women receiving therapy, 9 had OP and 19 had OST. Therapy was indicated in 18.4% for OP and 79.2% for OST. CONCLUSION: A preventive measurement of BMD with DXA provides a benefit for postmenopausal women. Combinatory assessment and consideration of other risk factors allows identification of women who might benefit from early treatment.

A photometric redshift of z = 6.39 +/- 0.12 for GRB 050904.

Gamma-ray bursts (GRBs) and their afterglows are the most brilliant transient events in the Universe. Both the bursts themselves and their afterglows have been predicted to be visible out to redshifts of z approximately 20, and therefore to be powerful probes of the early Universe. The burst GRB 000131, at z = 4.50, was hitherto the most distant such event identified. Here we report the discovery of the bright near-infrared afterglow of GRB 050904 (ref. 4). From our measurements of the near-infrared afterglow, and our failure to detect the optical afterglow, we determine the photometric redshift of the burst to be z = 6.39 - 0.12 + 0.11 (refs 5-7). Subsequently, it was measured spectroscopically to be z = 6.29 +/- 0.01, in agreement with our photometric estimate. These results demonstrate that GRBs can be used to trace the star formation, metallicity, and reionization histories of the early Universe.

An optical supernova associated with the X-ray flash XRF 060218.

Long-duration gamma-ray bursts (GRBs) are associated with type Ic supernovae that are more luminous than average and that eject material at very high velocities. Less-luminous supernovae were not hitherto known to be associated with GRBs, and therefore GRB-supernovae were thought to be rare events. Whether X-ray flashes--analogues of GRBs, but with lower luminosities and fewer gamma-rays--can also be associated with supernovae, and whether they are intrinsically 'weak' events or typical GRBs viewed off the axis of the burst, is unclear. Here we report the optical discovery and follow-up observations of the type Ic supernova SN 2006aj associated with X-ray flash XRF 060218. Supernova 2006aj is intrinsically less luminous than the GRB-supernovae, but more luminous than many supernovae not accompanied by a GRB. The ejecta velocities derived from our spectra are intermediate between these two groups, which is consistent with the weakness of both the GRB output and the supernova radio flux. Our data, combined with radio and X-ray observations, suggest that XRF 060218 is an intrinsically weak and soft event, rather than a classical GRB observed off-axis. This extends the GRB-supernova connection to X-ray flashes and fainter supernovae, implying a common origin. Events such as XRF 060218 are probably more numerous than GRB-supernovae.

A short gamma-ray burst apparently associated with an elliptical galaxy at redshift z = 0.225.

Gamma-ray bursts (GRBs) come in two classes: long (> 2 s), soft-spectrum bursts and short, hard events. Most progress has been made on understanding the long GRBs, which are typically observed at high redshift (z approximately 1) and found in subluminous star-forming host galaxies. They are likely to be produced in core-collapse explosions of massive stars. In contrast, no short GRB had been accurately (< 10'') and rapidly (minutes) located. Here we report the detection of the X-ray afterglow from--and the localization of--the short burst GRB 050509B. Its position on the sky is near a luminous, non-star-forming elliptical galaxy at a redshift of 0.225, which is the location one would expect if the origin of this GRB is through the merger of neutron-star or black-hole binaries. The X-ray afterglow was weak and faded below the detection limit within a few hours; no optical afterglow was detected to stringent limits, explaining the past difficulty in localizing short GRBs.

Diagnostic management of benign and malignant pheochromocytoma.

As rare and thus often overlooked hormone-secreting tumors, pheochromocytomas pose a particular diagnostic challenge. Difficulties involve biochemical confirmation, localizing, and detection of malignancy. Measurement of free plasma metanephrines, genetic testing and specific imaging procedures--such as MIBG and octreotide scintigraphy or fluorodopamine PET--represent a considerable progress, and the management of benign pheochromocytomas has become very effective. However, a comparable improvement in the prognosis of malignant chromaffin cell tumors, which occur in approximately 10-15% of all cases, has not yet been achieved. Here, telomerase catalytic subunit (hTERT) activity and heat shock protein 90 expression could serve both as molecular markers allowing an earlier diagnosis of malignancy and as therapeutic targets. Familial syndromes should be considered both in benign and malignant pheochromocytoma, and should be tested for prior to surgery in selected patient groups.

Predictive Value of Asphericity in Pretherapeutic [111In]DTPA-Octreotide SPECT/CT for Response to Peptide Receptor Radionuclide Therapy with [177Lu]DOTATATE.

PURPOSE: The purpose of this study was to assess the value of the spatial heterogeneity of somatostatin receptor (SSR) volume, quantified as asphericity (ASP), and to predict response to peptide receptor radionuclide therapy (PRRT) in patients with metastatic gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN). PROCEDURES: From June 2011 to May 2013, patients suffering from GEP-NEN who underwent pretherapeutic [111In-DTPA0]octreotide scintigraphy (Octreoscan®) prior to [177Lu-DOTA0-Tyr3]octreotate ([177Lu]DOTATATE)-PRRT were enrolled in this retrospective evaluation. SSR expression in 20 NEN patients was qualitatively and quantitatively assessed using the Krenning score, the metastasis to liver uptake ratio (M/L ratio), and ASP at baseline. Response to PRRT was evaluated based on lesions, which were classified as responding lesions (RL) and non-responding lesions (NRL) after 4- and 12-month follow-ups. The values of the Krenning score, M/L ratio, and ASP for response prediction were compared by using the Mann-Whitney U test, Kruskal-Wallis test, and receiver operating characteristic (ROC) curves. RESULTS: Seventy-seven metastases (liver, n = 40; lymph node, n = 24; bone, n = 11; pancreas, n = 2) showed SSR expression. A higher ASP level was significantly associated with poorer response at both time points. ROC analyses revealed the highest area under the curve (AUC) for discrimination between RL and NRL for ASP after 4 months (AUC 0.97; p = 0.019) and after 12 months (AUC 0.96; p < 0.001), followed by the Krenning score (AUC 0.74; p = 0.082 and AUC 0.85; p < 0.001, respectively) and M/L ratio (AUC 0.77; p = 0.107 and AUC 0.82; p < 0.001). The optimal cutoff value for ASP was 5.12 % (sensitivity, 90 %; specificity, 93 %). CONCLUSION: Asphericity of SSR-expressing lesions in pretherapeutic single-photon emission computed tomography with integrated computed tomography (SPECT/CT) is a promising parameter for predicting response to PRRT in gastroenteropancreatic neuroendocrine neoplasms.

[Microalbuminuria in diabetes: setting the points for treatment]. / Mikroalbuminurie bei Diabetes: Nicht nur den Nieren droht Gefahr.

Both type 1 and type 2 diabetes mellitus have a cumulative risk of 25-40% for the development of microalbuminuria 25 years into the disease. In type 2 diabetes micro- and macroangiopathic complications, and frequently hypertension, may also develop. This means that the risk of a type 2 diabetic with microalbuminuria of developing cardiovascular disease is three times greater than that of a diabetic with no renal involvement. Annual screening for microalbuminuria should therefore be obligatory. An increasing albumin excretion rate (AER) is considered an indication for an elevated cardiovascular risk. Studies have shown that the rate of cardiovascular events in diabetics with microalbuminuria and hypertension can be reduced only by the combined treatment of hypertension, hyperglycemia, hyperlipidemia and microalbuminuria.

Overview of diagnostic performance and results for the first operation phase in Wendelstein 7-X (invited).

Wendelstein 7-X, a superconducting optimized stellarator built in Greifswald/Germany, started its first plasmas with the last closed flux surface (LCFS) defined by 5 uncooled graphite limiters in December 2015. At the end of the 10 weeks long experimental campaign (OP1.1) more than 20 independent diagnostic systems were in operation, allowing detailed studies of many interesting plasma phenomena. For example, fast neutral gas manometers supported by video cameras (including one fast-frame camera with frame rates of tens of kHz) as well as visible cameras with different interference filters, with field of views covering all ten half-modules of the stellarator, discovered a MARFE-like radiation zone on the inboard side of machine module 4. This structure is presumably triggered by an inadvertent plasma-wall interaction in module 4 resulting in a high impurity influx that terminates some discharges by radiation cooling. The main plasma parameters achieved in OP1.1 exceeded predicted values in discharges of a length reaching 6 s. Although OP1.1 is characterized by short pulses, many of the diagnostics are already designed for quasi-steady state operation of 30 min discharges heated at 10 MW of ECRH. An overview of diagnostic performance for OP1.1 is given, including some highlights from the physics campaigns.

Giant intrasellar carotid aneurysm - an unusual cause of panhypopituitarism.

Carotid artery aneurysms represent a very rare cause of pituitary failure. We describe the case of a female patient harbouring a giant aneurysm of the left carotid artery that subsequently led to panhypopituitarism. Interestingly, the late postoperative course was complicated by severe hyponatremia, whose origin may have been due to inappropriate ADH secretion. This case illustrates the problems of diagnosis and postoperative handling of panhypopituitarism due to an intrasellar aneurysm.

Role of ultrasound in the diagnosis of thyroid autonomy.

The role and the different technical modes of ultrasound in thyroid autonomy are discussed. B-mode sonography is routinely employed to e.g. calculate thyroid and nodule volume, describe the echo pattern of both the thyroid gland and focal lesions and to visualize neighboring organs such as lymph nodes. Sonography thus possesses a complementary role to scintigraphy, since it may further aid in the localization of toxic adenomas, in particular when they are dorsally located or it may change the therapeutic decision. An example for the latter would be the preference of a surgical approach in case of cystic degeneration of an autonomously functioning nodule. Recently, color-coded doppler sonography using color flow mapping has been employed. With the advent of this technique it has become possible to describe the pattern of vascularization in thyroid focal lesions such as rim perfusion or internal hypervascularization. This technique harbors a high sensitivity for toxic adenoma exhibiting high internal blood flow, but does not appear to reliably discriminate between benign and malignant lesions. Nevertheless, further improvement of this technique may be promising in further characterizing the functional status of sonographically detected lesions and in the prognostic assessment of post-treatment outcome.

Diagnostic strategies and surgical procedures in persistent or recurrent primary hyperparathyroidism.

The incidence of persistent or recurrent primary hyperparathyroidism reported in the literature lies between 1 and 10%. The main causes are represented by atypical locations or incorrect diagnosis of primary parathyroid hyperplasia. Since primary parathyroidectomy by an experienced surgeon has a success rate of 95%, there is no need for extended imaging studies prior to initial bilateral exploration. After confirming diagnosis of persistent or recurrent hyperparathyroidism exact localization studies are necessary. The most important procedures are ultrasonography, magnetic resonance imaging, technetium Tc99m sestamibi scintigraphy with a combined sensitivity of approximately 90%. In case of negative imaging results selective venous catheterization before reoperation can be performed. Reoperation by an experienced surgeon will be successful in 95% of cases.

Retroperitoneal schwannoma presenting as an adrenal tumor.

A retroperitoneal tumor in the region of the adrenal gland was diagnosed in a 56-year-old woman. The patient had been suffering from a dull abdominal pain for nearly four weeks before consulting her family physician. Ultrasound, CT and MRI scans revealed a giant tumor of the right adrenal gland. Endocrine activity could not be demonstrated. The size of the tumor was suggestive of an adrenal carcinoma. The patient was referred for adrenalectomy and complete exstirpation of the retroperitoneal mass. The histological examination revealed characteristical findings of a benign schwannoma.

[Determination of renal clearance with only a single access for injection and blood extraction]. / Bestimmung der renalen Clearance mit nur einem Zugang für Injektion und Blutentnahme.

An injection technique was developed to administer radioactivity to children and adults and to withdraw plasma samples through the same venous line. The error in clearance estimation due to "contamination" was smaller than that caused by the timing of blood sampling or the type of algorithm used for clearance calculation.