Complementary and alternative medicine and musculoskeletal pain in the first year of adjuvant aromatase inhibitor treatment in early breast cancer patients.

BACKGROUND: Patients with breast cancer (BC) show strong interest in complementary and alternative medicine (CAM), particularly for adverse effects of adjuvant endocrine treatment - e.g., with letrozole. Letrozole often induces myalgia/limb pain and arthralgia, with potential noncompliance and treatment termination. This analysis investigated whether CAM before aromatase inhibitor (AI) therapy is associated with pain development and the intensity of AI-induced musculoskeletal syndrome (AIMSS) during the first year of treatment. PATIENTS AND METHODS: The multicenter phase IV PreFace study evaluated letrozole therapy in postmenopausal, hormone receptor-positive patients with early BC. Patients were asked about CAM use before, 6 months after, and 12 months after treatment started. They recorded pain every month for 1 year in a diary including questions about pain and numeric pain rating scales. Data were analyzed for patients who provided pain information for all time points. RESULTS: Of 1396 patients included, 901 (64.5%) had used CAM before AI treatment. Throughout the observation period, patients with CAM before AI treatment had higher pain values, for both myalgia/limb pain and arthralgia, than non-users. Pain increased significantly in both groups over time, with the largest increase during the first 6 months. No significant difference of pain increase was noted regarding CAM use. CONCLUSIONS: CAM use does not prevent or improve the development of AIMSS. Pain intensity was generally greater in the CAM group. Therefore, because of the risk of non-compliance and treatment discontinuation due to the development of higher pain levels, special attention must be paid to patient education and aftercare in these patients.

Haemostasis in oral surgical procedures involving patients with a ventricular assist device.

The purpose of this study was to determine whether tooth extraction for patients with ventricular assist devices (VADs) could be performed without interruption of anticoagulant and/or antiplatelet therapy and whether treatment with von Willebrand factor concentrates and desmopressin is required. The study consisted of three groups of patients undergoing oral surgery. The two experimental groups comprised patients with VADs, while the third group included cardiovascular patients without VADs who served as controls. All patients were treated intraoperatively with topical haemostatic agents (oxidized cellulose or collagen). The first group was additionally treated with fibrin glue. All 75 oral surgical procedures were performed under local anaesthesia without sedation. Three of 40 patients in the experimental groups and two of 20 patients in the control group suffered a haemorrhage, with no significant difference in the incidence of haemorrhage between the groups. The findings suggest that dental extraction can be performed without modification of oral anticoagulation or antiplatelet treatments, providing that INR is less than 3.5 on the day of the operation. It can further be hypothesized that an acquired coagulopathy in VAD patients does not influence the bleeding risk in dental extractions, and so the administration of desmopressin and/or von Willebrand factor concentrates is not required.

Mechanical endurance and in vivo radiographic analysis of a flexible, mono-unit cervical disc implant in intermediate follow-up period.

AIM: The flexible artificial disc may create a system with a biomimetic structure that has the potential to tolerate dynamic motion in a way similar to a normal intervertebral disc over a long period. The objective was to evaluate the mechanical feasibility and clinical and radiological findings with a mono-unit and flexible artificial disc at intermediate-term follow-up. METHODS: Fifty-six patients with degenerative disc disease were selected to participate in the study. They underwent discectomy with a flexible artificial disc with a mean follow-up period of 24.8 months. Outcomes were evaluated with the visual analogue scale (VAS) and Oswestry Disability Index (ODI). Mechanical endurance was evaluated by a dynamic testing. RESULTS: Fifty one-levels and six bi-levels were included in the study (average age 41.8 years). VAS improved from 6.8 ± 2.2 to 1.5 ± 1.7 (P<0.05) and ODI improved from 43.1 ± 10.4 to 18.2 ± 10.2 (P<0.05). Disc height before mechanical testing was 8.9 mm, and decreased to 8.4 mm after six million cycles with no mechanical failure. CONCLUSION: Our results indicate that flexible and mono-unit cervical disc provides favorable mechanical performance and clinical outcomes for at least a relatively intermediate-term follow up period. It is indicated that the flexible cervical disc maintains mobility at the level of the prosthesis that is comparable with preoperative ranges of motion. Further evaluation will be completed once long-term results have been obtained.

How good is the levothyroxine replacement in primary hypothyroidism patients in Brazil? Data of a multicentre study.

BACKGROUND: Studies from every continent have shown that only around 50% of the patients subjected to thyroid hormone replacement have TSH in the normal range. However, to date, there are no consistent data about Brazil. OBJECTIVES: To evaluate levothyroxine (LT4) replacement treatment in patients with primary hypothyroidism followed in referral centers in Brazil. METHODS: Patients with primary hypothyroidism followed in referral centers (University Hospitals from Universidade Federal do Rio de Janeiro - UFRJ, Unicamp, Universidade Federal do Paraná - UFPR and Universidade Federal do Ceará-UFC) answered a questionnaire that inquired about clinical and biochemical conditions, social- economic status, life quality and clinicians' orientations as well as their understanding about the information given. Serum TSH was checked close to the interview. RESULTS: 2292 consecutive patients met the inclusion criteria. Mean age 51.2 yr and TSH values between 0.4 and 4.0 mUI/l were considered to be within the reference range. Among all patients taking thyroid medication, 42.7% had an abnormal serum TSH (28.3% were undertreated and 14.4% were overtreated). Approximately all patients (99%) took LT4 in the morning but less than 30 min before breakfast (85.4%). Regarding the clinicians' orientations: 97.5% of the patients were instructed to take the medication daily, and 92.6% to take 30 min before breakfast (92.6%). However, only 52.1% were told not to take LT4 along with other medication. CONCLUSIONS: Our study found that a significant number of patients taking thyroid hormones were not in the therapeutic range. Clinicians should, therefore, consider monitoring patients on thyroid replacement more frequently and being more precise on giving recommendations about the correct use of LT4.

Modified-release recombinant human TSH (MRrhTSH) augments the effect of (131)I therapy in benign multinodular goiter: results from a multicenter international, randomized, placebo-controlled study.

BACKGROUND: Recombinant human TSH (rhTSH) can be used to enhance (131)I therapy for shrinkage of multinodular goiter (MG). OBJECTIVE, DESIGN, AND SETTING: The objective of the study was to compare the efficacy and safety of 0.01 and 0.03 mg modified-release (MR) rhTSH as an adjuvant to (131)I therapy, vs. (131)I alone, in a randomized, placebo-controlled, international, multicenter study. PATIENTS AND INTERVENTION: Ninety-five patients (57.2 ± 9.6 yr old, 85% females, 83% Caucasians) with MG (median size 96.0, range 31.9-242.2 ml) were randomized to receive placebo (group A, n = 32), MRrhTSH 0.01 mg (group B, n = 30), or MRrhTSH 0.03 mg (group C, n = 33) 24 h before a calculated activity of (131)I. MAIN OUTCOME MEASURES: The primary end point was a change in thyroid volume (by computerized tomography scan, at 6 months). Secondary end points were the smallest cross-sectional area of the trachea; thyroid function tests; Thyroid Quality of Life Questionnaire; electrocardiogram; and hyperthyroid symptom scale. RESULTS: Thyroid volume decreased significantly in all groups. The reduction was comparable in groups A and B (23.1 ± 8.8 and 23.3 ± 16.5%, respectively; P = 0.95). In group C, the reduction (32.9 ± 20.7%) was more pronounced than in groups A (P = 0.03) and B. The smallest cross-sectional area of the trachea increased in all groups: 3.8 ± 2.9% in A, 4.8 ± 3.3% in B, and 10.2 ± 33.2% in C, with no significant difference among the groups. Goiter-related symptoms were effectively reduced and there were no major safety concerns. CONCLUSION: In this dose-selection study, 0.03 mg MRrhTSH was the most efficacious dose as an adjuvant to (131)I therapy of MG. It was well tolerated and significantly augmented the effect of (131)I therapy in the short term. Larger studies with long-term follow-up are warranted.

Radioiodine plus recombinant human thyrotropin do not cause acute airway compression and are effective in reducing multinodular goiter.

Recombinant human thyrotropin (rhTSH) reduces the activity of radioiodine required to treat multinodular goiter (MNG), but acute airway compression can be a life-threatening complication. In this prospective, randomized, double-blind, placebo-controlled study, we assessed the efficacy and safety (including airway compression) of different doses of rhTSH associated with a fixed activity of 131I for treating MNG. Euthyroid patients with MNG (69.3 +/- 62.0 mL, 20 females, 2 males, 64 +/- 7 years) received 0.1 mg (group I, N = 8) or 0.01 mg (group II, N = 6) rhTSH or placebo (group III, N = 8), 24 h before 1.11 GBq 131I. Radioactive iodine uptake was determined at baseline and 24 h after rhTSH and thyroid volume (TV, baseline and 6 and 12 months after treatment) and tracheal cross-sectional area (TCA, baseline and 2, 7, 180, and 360 days after rhTSH) were determined by magnetic resonance; antithyroid antibodies and thyroid hormones were determined at frequent intervals. After 6 months, TV decreased significantly in groups I (28.5 +/- 17.6%) and II (21.6 +/- 17.8%), but not in group III (2.7 +/- 15.3%). After 12 months, TV decreased significantly in groups I (36.7 +/- 18.1%) and II (37.4 +/- 27.1%), but not in group III (19.0 +/- 24.3%). No significant changes in TCA were observed. T3 and free T4 increased transiently during the first month. After 12 months, 7 patients were hypothyroid (N = 3 in group I and N = 2 in groups II and III). rhTSH plus a 1.11-GBq fixed 131I activity did not cause acute or chronic changes in TCA. After 6 and 12 months, TV reduction was more pronounced among patients treated with rhTSH plus 131I.

Radioiodine plus recombinant human thyrotropin do not cause acute airway compression and are effective in reducing multinodular goiter

Recombinant human thyrotropin (rhTSH) reduces the activity of radioiodine required to treat multinodular goiter (MNG), but acute airway compression can be a life-threatening complication. In this prospective, randomized, double-blind, placebo-controlled study, we assessed the efficacy and safety (including airway compression) of different doses of rhTSH associated with a fixed activity of 131I for treating MNG. Euthyroid patients with MNG (69.3 ± 62.0 mL, 20 females, 2 males, 64 ± 7 years) received 0.1 mg (group I, N = 8) or 0.01 mg (group II, N = 6) rhTSH or placebo (group III, N = 8), 24 h before 1.11 GBq 131I. Radioactive iodine uptake was determined at baseline and 24 h after rhTSH and thyroid volume (TV, baseline and 6 and 12 months after treatment) and tracheal cross-sectional area (TCA, baseline and 2, 7, 180, and 360 days after rhTSH) were determined by magnetic resonance; antithyroid antibodies and thyroid hormones were determined at frequent intervals. After 6 months, TV decreased significantly in groups I (28.5 ± 17.6 percent) and II (21.6 ± 17.8 percent), but not in group III (2.7 ± 15.3 percent). After 12 months, TV decreased significantly in groups I (36.7 ± 18.1 percent) and II (37.4 ± 27.1 percent), but not in group III (19.0 ± 24.3 percent). No significant changes in TCA were observed. T3 and free T4 increased transiently during the first month. After 12 months, 7 patients were hypothyroid (N = 3 in group I and N = 2 in groups II and III). rhTSH plus a 1.11-GBq fixed 131I activity did not cause acute or chronic changes in TCA. After 6 and 12 months, TV reduction was more pronounced among patients treated with rhTSH plus 131I.

[Painful swollen leg 52 years after bimalleolar fracture]. / Schmerzhafte Unterschenkelschwellung 52 Jahre nach Bimalleolarfraktur.

Calcific myonecrosis is a late complication of a previous trauma which presents as a calcified fusiforme mass on an x-ray film. It is affecting mostly the anterior compartment of the lower leg. 43 cases have been reported in the literature and are reviewed. The current authors report a case of calcific myonecrosis with calcific tenosynovitis of the tibialis anterior muscle. Precipitated hydroxyapatite crystals were found by ultrasound-guided aspiration, the lesion was then treated by injection of corticosteroids and an anesthetic.

Wound healing in colonic anastomosis in hypothyroidism.

Colonic anastomosis healing in hypothyroidism was evaluated. Twenty Wistar rats were separated into two groups: the study group (n = 10), which underwent total thyroidectomy to induce hypothyroidism, and the control group (n = 10). After 10 weeks, hypothyroid status was confirmed by blood tests (p < 0.0001). Three days later, a colonic anastomosis was performed, and the animals were sacrificed 1 week later. The colon containing the anastomosis was resected for bursting strength tests and histological studies. The slides were stained with hematoxylin-eosin and with Sirius red to quantify and classify the collagen. Reduced values were found for the bursting strength test (p = 0.0006) and for collagen density in the experimental group. There was a prevalence of immature type III collagen (p < 0.0001) and a decrease in mature type I collagen (p < 0.0001) in the hypothyroid group.

Recombinant human TSH increases the efficacy of a fixed activity of radioiodine for treatment of multinodular goitre.

CONTEXT: High doses of (131)I are usually needed in the treatment of multinodular goitre (MNG) for effective thyroid volume (TV) reduction. Recombinant human thyroid-stimulating hormone (rhTSH) is an adjuvant to enhance (131)I uptake, allowing a decrease in radiation activity and enhancing (131)I efficacy. OBJECTIVE: To evaluate whether rhTSH increases the efficacy of a fixed activity of (131)I for the treatment of MNG. DESIGN: Two-year, observational, placebo-controlled study. SETTING: Patients received 0.1 mg rhTSH (A), 0.005 mg rhTSH (B) or placebo (C). A fixed activity of 1.11 GBq of (131)I was administered 24 h after rhTSH or placebo. PATIENTS: A total of 28 outpatients (26 females and two males) with MNG. MEASUREMENTS: TSH, free T4, T3, thyroglobulin (Tg) and TV. RESULTS: Basal radioactive iodine uptake and TV values were comparable among all groups. After rhTSH or placebo, peak levels of TSH, free T4, T3 and Tg were higher in A than in B or in C (p < 0.05). Hyperthyroidism was observed in A (n = 2), B (n = 6) and C (n = 4). Thyroid enlargement was reported in A (n = 3) and B (n = 6). After 24 months, 10 patients developed hypothyroidism (four in A, three in B and three in C). TV reduction was similar between A and B (37.2 +/- 25.5% vs. 39.3 +/- 27.9%, p = 0.88), but different from the non-significant reduction in C (15.3 +/- 28.3%, p = 0.08). CONCLUSIONS: Followed by 1.11 GBq, a very low dose of 0.005 mg rhTSH was equally safe and effective as 0.1 mg rhTSH. Both doses increased the efficacy of radioiodine. Adverse events were mild, transient and readily treatable.

Postprandial intradialytic dysglycaemia and diabetes in maintenance haemodialysis patients.

BACKGROUND: Although the risk of developing dysglycaemia has been investigated in different communities this incidence is poorly studied in patients on maintenance haemodialysis (MHD). MATERIALS AND METHODS: In a multicentre observational cohort study the occurrence of dysglycaemia was assessed in 239 primary normoglycaemic end stage renal disease (ERSD) patients on MHD. Dysglycaemia (fasting blood glucose > 110 mg dL(-1), > 140 mg dL(-1) 2 h after food intake) or diabetes (fasting blood glucose > 126 mg dL(-1) or > 200 mg dL(-1) at any time) were defined according to WHO criteria and cases were compared with age matched controls within the cohort. RESULTS: Dysglycaemia was found in 82 primary normoglycaemic ESRD patients (34%) within 31 months after initiation of MHD. In 31 of these patients type 2 diabetes was diagnosed. When compared with matched control MHD patients differences in body mass index (BMI), HbA1c and postprandial blood glucose were detectable (P < 0.05). Increments in 0.1% of HbA1c were related with 11% higher odds for dysglycaemia (P = 0.002). In a subgroup of 36 primary normoglycaemic MHD patients who developed dysglycaemia event-free survival was 64%, 53%, 31%, 17% and 11% after 1, 2, 3, 4 and 5 years of haemodialysis treatment. CONCLUSION: Onset of dysglycaemia or diabetes is frequent in ESRD patients after onset of chronic haemodialysis. Routine measurement of blood glucose before and after haemodialysis should be implemented as a standard of care during MHD.

Effect of bone sialoprotein and collagen coating on cell attachment to TICER and pure titanium implant surfaces.

To improve integration between implants and biological tissues, this study compared bone sialoprotein (BSP) as a surface-coating material against the major organic and inorganic components of bone, collagen type I and hydroxyapatite (TICER). The expression of osteocalcin, osteonectin and transforming growth factor ss was evaluated using immunohistochemical staining procedures. The distribution patterns of osteoblasts on the surface of pure titanium with a smooth machined surface and a rough surface (TICER) were determined by image processing using confocal laser scanning microscopy. The results compared to uncoated control materials showed that, at all times investigated, the number of cells on the surface of the TICER and pure titanium samples differed significantly (P<0.1), demonstrating the superiority of TICER over pure titanium in this respect. For pure titanium implants, collagen-precoated surfaces were not beneficial for the attachment of bone-derived cells with the exception of day 3 in vitro (P<0.01). BSP-precoated implant surfaces displayed non-significantly higher numbers of settled cells. BSP-precoated implant surfaces were beneficial for osteoinduction as revealed by osteocalcin and osteonectin expression. BSP precoating of the rough TICER implant surface enhanced the osteoinductive effect much more than did collagen precoating. These results contribute to the consideration of at least two distinct pathways of osseointegration.

Preparation and characterization of selenium incorporated anodic conversion coatings on titanium surfaces for biomedical applications.

An anodic spark deposition process was used for preparation of inorganic, glass-ceramic like conversion coatings. The microstructure of the layers was characterized by surface and solid state techniques such as scanning electron microscopy, electron probe microanalysis and Raman spectroscopy. The porous coatings, typically up to 8 mum thick, consist mainly of titanium oxides and amounts of incorporated electrolyte constituents like Se, Ca or P. Beside nano crystalline anatase phases, a mostly amorphous structure is proposed in which network-forming [PO(4)] tetrahedras and [TiO(6)] octahedras in various degrees of condensation are connected. A drastic modification of the film structure was observed when selenium was incorporated into the glassy oxide structure of the coating. In these cases no nano crystalline phases of titanium oxides or other chemical compounds were detected. First cell culture investigations show a significant improvement of the biological properties. Cell proliferation and TGF-beta-expression of these coatings in comparison with commercial pure titanium (CPT) with native titanium oxide films were examined.

Effect of 30 mCi radioiodine on multinodular goiter previously treated with recombinant human thyroid-stimulating hormone

Recombinant human thyroid-stimulating hormone (rhTSH) enhances 131I uptake, permitting a decrease in radiation for the treatment of multinodular goiter (MNG). Our objective was to evaluate the safety and efficacy of a single 0.1-mg dose of rhTSH, followed by 30 mCi 131I, in patients with MNG. Seventeen patients (15 females, 59.0 ± 13.1 years), who had never been submitted to 131I therapy, received a single 0.1-mg injection of rhTSH followed by 30 mCi 131I on the next day. Mean basal thyroid volume measured by computed tomography was 106.1 ± 64.4 mL. 131I 24-h uptake, TSH, free-T4, T3, thyroglobulin, anti-thyroid antibodies, and thyroid volume were evaluated at regular intervals of 12 months. Mean 131I 24-h uptake increased from 18.1 ± 9.7 to 49.6 ± 13.4 percent (P < 0.001), a median 2.6-fold increase (1.2 to 9.2). Peak hormonal levels were 10.86 ± 5.44 mU/L for TSH (a median 15.5-fold increase), 1.80 ± 0.48 ng/dL for free-T4, 204.61 ± 58.37 ng/dL for T3, and a median of 557.0 ng/mL for thyroglobulin. The adverse effects observed were hyperthyroidism (17.6 percent), painful thyroiditis (29.4 percent) and hypothyroidism (52.9 percent). Thyroid volume was reduced by 34.3 ± 14.3 percent after 6 months (P < 0.001) and by 46.0 ± 14.6 percent after 1 year (P < 0.001). Treatment of MNG with a single 0.1-mg dose of rhTSH, followed by a fixed amount of radioactivity of 131I, leads to an efficacious decrease in thyroid volume for the majority of the patients, with a moderate incidence of non-serious and readily treatable adverse effects.

Effect of 30 mCi radioiodine on multinodular goiter previously treated with recombinant human thyroid-stimulating hormone.

Recombinant human thyroid-stimulating hormone (rhTSH) enhances 131I uptake, permitting a decrease in radiation for the treatment of multinodular goiter (MNG). Our objective was to evaluate the safety and efficacy of a single 0.1-mg dose of rhTSH, followed by 30 mCi 131I, in patients with MNG. Seventeen patients (15 females, 59.0 +/- 13.1 years), who had never been submitted to 131I therapy, received a single 0.1-mg injection of rhTSH followed by 30 mCi 131I on the next day. Mean basal thyroid volume measured by computed tomography was 106.1 +/- 64.4 mL. 131I 24-h uptake, TSH, free-T4, T3, thyroglobulin, anti-thyroid antibodies, and thyroid volume were evaluated at regular intervals of 12 months. Mean 131I 24-h uptake increased from 18.1 +/- 9.7 to 49.6 +/- 13.4% (P < 0.001), a median 2.6-fold increase (1.2 to 9.2). Peak hormonal levels were 10.86 +/- 5.44 mU/L for TSH (a median 15.5-fold increase), 1.80 +/- 0.48 ng/dL for free-T4, 204.61 +/- 58.37 ng/dL for T3, and a median of 557.0 ng/mL for thyroglobulin. The adverse effects observed were hyperthyroidism (17.6%), painful thyroiditis (29.4%) and hypothyroidism (52.9%). Thyroid volume was reduced by 34.3 +/- 14.3% after 6 months (P < 0.001) and by 46.0 +/- 14.6% after 1 year (P < 0.001). Treatment of MNG with a single 0.1-mg dose of rhTSH, followed by a fixed amount of radioactivity of 131I, leads to an efficacious decrease in thyroid volume for the majority of the patients, with a moderate incidence of non-serious and readily treatable adverse effects.

Implant surface coatings with bone sialoprotein, collagen, and fibronectin and their effects on cells derived from human maxillar bone.

The interaction between implant material and surrounding tissues is believed to play a fundamental role in implant success. Although bone sialoprotein (BSP) has been found to be osteoinductive when coated onto femoral implants, collagen and fibronectin are the most used compounds for preparation of pre-coated cell culture slides at present. In this study, the support of BSP-, collagen- and fibronectin-coated and non-coated implant material for the development of adult human maxillar bone in vitro was studied and compared. The expression of bone turnover markers like BSP and osteocalcin as well as osteonectin, transforming growth factor beta (TGF-beta) and CD90 during different time periods of cell cultivation (3, 5, 10, 15, 20 and 25 days) was visualized immunohistochemically. The distribution patterns of the cells were examined on a rough surface of the titanium-hydroxyapatite dental implant material TICER and on a total smooth surface of the technical implant material glimmer. Significantly different values were found for glimmer at the 15. and the 20. Div, exclusively, indicating that a smooth surface was more improved than a rough ceramic surface by pre-coatings. The White-test using rankings of the median values gave evidence for BSP-coatings at position 1 followed by collagen. Our experiments were designed to use very low concentrated BSP coating solution with the aim to reduce the healing time with a minimal effort and minimal risks for the patients.

High resolution MR perfusion imaging of the kidneys at 3 Tesla without administration of contrast media.

PURPOSE: The feasibility of high-resolution arterial spin labeling (ASL) perfusion imaging of the kidneys was tested and proven at 3 Tesla using a flow-sensitive alternating inversion recovery (FAIR) true fast imaging in steady precession (TrueFISP) technique. MATERIALS AND METHODS: Kidney perfusion maps of six healthy volunteers and two patients were acquired using a clinical 3-Tesla whole-body scanner. An ASL sequence with FAIR spin preparation and a TrueFISP signal detection strategy was adapted for high-resolution perfusion imaging of the kidneys at 3 Tesla. To avoid banding artifacts in TrueFISP images, which are generally prominent at 3 Tesla, a frequency scout was implemented. Perfusion maps with an in-plane resolution of 1.5 mm were recorded in transverse and coronal orientation. For fast mapping of whole-kidney perfusion, an in-plane resolution of 2 mm was applied. RESULTS: In all volunteers and patients, high-resolution perfusion images with excellent image quality were able to be obtained in a measuring time of approximately 10 minutes. The whole kidney was able to be mapped with good image quality in less than 10 minutes. For all slices, a suitable frequency offset made it possible to reproduce the kidneys without TrueFISP artifacts. Perfusion values of the renal cortex ranged from 250 ml/100 g/min up to 400 ml/100 g/min (mean cortical perfusion right kidney 316 +/- 43, left 336 +/- 40). CONCLUSION: High-resolution ASL perfusion images of the whole kidney were able to be obtained with good image quality by means of a 3 Tesla MR setting within a clinically applicable measuring time, thus providing an alternative to conventional perfusion imaging involving potentially nephrotoxic contrast media.

Experimental investigations of chaos-assisted tunneling in a microwave annular billiard.

We present detailed investigations of the experimental signatures of chaos-assisted tunneling in the two-dimensional annular billiard, as already summarized in Phys. Rev. Lett. 84, 867 (2000). We have performed analog experiments with two-dimensional, electromagnetic resonators allowing for a direct simulation of the corresponding quantum system. Spectra from a superconducting cavity with a high-frequency resolution are combined with electromagnetic intensity distributions of high spatial resolution experimentally determined using a normal conducting twin cavity. Thereby all eigenmodes were obtained with properly identified quantum numbers. Besides distributions of quasi-doublet splittings, which serve as fundamental observables for the tunneling between whispering gallery types of modes, we also focus on the distributions of resonance widths of the doublets. These directly reflect the role of lifetime of certain modes in the tunneling process. Here, as theoretically expected, the class of so-called beach modes is found to play a particular role in mediating between regular and chaotic states to enhance the tunneling strength. This behavior is found in the spectrum and also in the structure of the wave functions.