This study compared different magnetic resonance imaging (MRI) methods with Tl(201) single photon emission computerized tomography (SPECT) and the "gold standard" for viability assessment, functional recovery after coronary artery bypass grafting (CABG). Twenty patients (64+/-7.3 years) with severely impaired left ventricular function (ejection fraction [EF] 28.6+/-8.7%) underwent MRI and SPECT before and 6 months after CABG. Wall-motion abnormalities were assessed by stress cine MRI using low-dose dobutamine. A segment with a nonreversible defect in Tl(201)-SPECT and a delayed enhancement (DE) in an area >50% of the entire segment, as well as an end-diastolic wall thickness <6 mm, was defined as nonviable. The mean postoperative EF (n=20) improved slightly from 28.6+/-8.7% to 32.2+/-12.4% (not significant). Using the Tl(201)-SPECT as the reference method, end-diastolic wall thickness, MRI-DE, and stress MRI showed high sensitivity of 94%, 93%, and 84%, respectively, but low specificities. Using the recovery of contractile function 6 months after CABG as the gold standard, MRI-DE showed an even higher sensitivity of 99%, end-diastolic wall thickness 96%, stress MRI 88%, and Tl(201)-SPECT 86%. MRI-DE showed advantages compared with the widely used Tl(201)-SPECT and all other MRI methods for predicting myocardial recovery after CABG.

No abstract

Objective: Iodide transport across thyrocytes constitutes a critical step for thyroid hormone biosynthesis, mediated mainly by the basolateral sodium-iodide-symporter (NIS) and the apical anion exchanger pendrin (PDS). Both transmembrane proteins have been described as autoantigens in thyroid disease, yet the reports on autoantibody (aAb) prevalence and diagnostic usefulness are conflicting. Reasons for the inconclusive findings may be small study groups and principle differences in the technologies used. Design: We decided to re-evaluate this important issue by establishing novel non-radioactive tests using full-length antigens and comparable protocols, and analysing a large cohort of thyroid patients (n=323) and control samples (n=400). Methods: NIS and PDS were recombinantly expressed as fusion protein with firefly luciferase (Luc). Stably transfected HEK293 cells were used as reproducible source of the autoantigens. Results: Recombinant NIS-Luc showed iodide transport activity, indicating successful expression and correct processing. Commercial antibodies yielded dose-dependent responses in the newly established assays. Reproducibility of assay signals from patient sera was verified with respect to linearity, stability and absence of matrix effects. Prevalence of PDS-aAb was similar in thyroid patients and controls (7.7% versus 5.0%). NIS-aAb were more prevalent in patients (7.7% versus 1.8%), especially in Graves’ Disease (12.3%). Neither NIS-aAb nor PDS-aAb concentrations were related to TPO-aAb or TSH-receptor-aAb concentrations, or to serum zinc or selenium status. Conclusions: Our data highlight a potential relevance of autoimmunity against NIS for thyroid disease, whereas an assessment of PDS-aAb in thyroid patients seems not to be of diagnostic value (yet).

Attenuation correction of SRS SPECT data by SPECT-CT results in visually more clearly contrasted foci. Moreover, as focus intensity increases, especially in the more centrally localised foci, CT-based AC has a potential to further improve the sensitivity of SRS SPECT.

The essential trace element selenium (Se) is needed for the biosynthesis of selenocysteine-containing selenoproteins, including the secreted enzyme glutathione peroxidase 3 (GPX3) and the Se-transporter selenoprotein P (SELENOP). Both are found in blood and thyroid colloid, where they serve protective functions. Serum SELENOP derives mainly from hepatocytes, whereas the kidney contributes most serum GPX3. Studies using transgenic mice indicated that renal GPX3 biosynthesis depends on Se supply by hepatic SELENOP, which is produced in protein variants with varying Se contents. Low Se status is an established risk factor for autoimmune thyroid disease, and thyroid autoimmunity generates novel autoantigens. We hypothesized that natural autoantibodies to SELENOP are prevalent in thyroid patients, impair Se transport, and negatively affect GPX3 biosynthesis. Using a newly established quantitative immunoassay, SELENOP autoantibodies were particularly prevalent in Hashimoto’s thyroiditis as compared with healthy control subjects (6.6% versus 0.3%). Serum samples rich in SELENOP autoantibodies displayed relatively high total Se and SELENOP concentrations in comparison with autoantibody-negative samples ([Se]; 85.3 vs. 77.1 µg/L, p = 0.0178, and [SELENOP]; 5.1 vs. 3.5 mg/L, p = 0.001), while GPX3 activity was low and correlated inversely to SELENOP autoantibody concentrations. In renal cells in culture, antibodies to SELENOP inhibited Se uptake. Our results indicate an impairment of SELENOP-dependent Se transport by natural SELENOP autoantibodies, suggesting that the characterization of health risk from Se deficiency may need to include autoimmunity to SELENOP as additional biomarker of Se status.

Background: Patients with chronic atherosclerotic vessel occlusion and cerebrovascular hemodynamic insufficiency may benefit from extra-intracranial (EC-IC) bypass surgery. Due to demographic changes, an increasing number of elderly patients presents with cerebrovascular hemodynamic insufficiency. So far, little data for EC-IC bypass surgery in elderly patients suffering occlusive cerebrovascular disease are available. We therefore designed a retrospective study to address the question whether EC-IC bypass is a safe and efficient treatment in a patient cohort ≥70 years. Methods: 50 patients underwent EC-IC standard bypass surgery with translocation of the superficial temporal artery to an M2 segment of the medial cerebral artery. Criteria for bypass surgery were presence of symptomatic occlusive cerebrovascular disease of the anterior circulation and proof of a severely restricted or abrogated reserve capacity (detected by H₂O-photon emission tomography or single photon emission computer tomography - before and after forced vessel dilatation by diamox). The incidence of perioperative neurological and surgical complications, bypass patency, bypass function and short-term outcome were retrospectively analyzed. Results: The study cohort consisted of 16 patients ≥70 years (mean = 74.3 years, SE 1.3). It was compared to a cohort of 34 patients <70 years (mean = 61.2 years, SE 1.0). Both groups underwent EC-IC bypass surgery after careful preoperative work-up. Both patient groups did not differ significantly in gender, vascular pathology, previous history of diseases/comorbidity or clinical symptoms. The number of patients which underwent stenting or other endovascular treatments of the internal or common carotid artery prior to EC-IC bypass surgery was significantly higher in the group of patients ≥70 years (37.5 vs. 0%, p < 0.001). Perioperative stroke rate was 0% in both groups and mild morbidity occurred in 18.8 and 14.7%, respectively (p = 0.699). One 84-year-old female patient died due to perioperative endocarditis. Initial bypass patency was 93.8% in patients above the age of 70 years and 97.1% in the younger group (p = 0.542). Secondary occlusion rate was low in both groups (≥70 years: 0% vs. <70 years 3.7%). No new neurologic deficit occurred in patients with a patent bypass during the follow-up period (median 18 ± 13.1 months). Two patients with an initially occluded bypass and one with a secondary bypass occlusion suffered from new neurological symptoms. Conclusions: Our data show comparable safety and efficiency of EC-IC bypass surgery in patients under and above the age of 70 years due to a careful preoperative work-up and a strict indication for bypass surgery.

Attenuation correction of somatostatin receptor scintigraphy-SPECT significantly improves focus visualization and, albeit slightly, also significantly increases sensitivity.

Neurodevelopmental diseases are often associated with other comorbidities, especially inflammatory processes. The disease may affect the trace element (TE) status, which in turn may affect disease severity and progression. Selenium (Se) is an essential TE required for the biosynthesis of selenoproteins including the transporter selenoprotein P (SELENOP) and extracellular glutathione peroxidase (GPX3). SELENOP deficiency in transgenic mice resulted in a Se status-dependent phenotype characterized by impaired growth and disturbed neuronal development, with epileptic seizures on a Se-deficient diet. Therefore, we hypothesized that Se and SELENOP deficiencies may be prevalent in paediatric patients with a neurodevelopmental disease. In an exploratory cross-sectional study, serum samples from children with neurodevelopmental diseases (n = 147) were analysed for total serum Se, copper (Cu), and zinc (Zn) concentrations as well as for the TE biomarkers SELENOP, ceruloplasmin (CP), and GPX3 activity. Children with epilepsy displayed elevated Cu and Zn concentrations but no dysregulation of serum Se status. Significantly reduced SELENOP concentrations were found in association with intellectual disability (mean ± SD (standard deviation); 3.9 ± 0.9 mg/L vs. 4.4 ± 1.2 mg/L, p = 0.015). A particularly low GPX3 activity (mean ± SD; 172.4 ± 36.5 vs. 192.6 ± 46.8 U/L, p = 0.012) was observed in phacomatoses. Autoantibodies to SELENOP, known to impair Se transport, were not detected in any of the children. In conclusion, there was no general association between Se deficiency and epilepsy in this observational analysis, which does not exclude its relevance to individual cases. Sufficiently high SELENOP concentrations seem to be of relevance to the support of normal mental development. Decreased GPX3 activity in phacomatoses may be relevant to the characteristic skin lesions and merits further analysis. Longitudinal studies are needed to determine whether the observed differences are relevant to disease progression and whether correcting a diagnosed TE deficiency may confer health benefits to affected children.