Timing of post 131I ablation diagnostic whole body scan in differentiated thyroid cancer patients

Ziel: Beantwortung der Frage, ob drei Monate nach 131I-Ablation als zu früh für eine diagnostische Radioiod-Ganzkörperszintigraphie (dxWBS) bei Patienten mit einem differenzierten Schilddrüsenkarzinom (DTC) anzusehen sind. Patienten, Material, Methode: Daten von 462 DTC-Patienten, die in unserem Klinikum behandelt worden waren, wurden analysiert. Alle Patienten wurden thyreoid ektomiert. Von 129 Patienten waren folgende Daten verfügbar a) eine dxWBS mit gleichzeitiger TSH-stimulierter Thyreoglobulin-Messung, die innerhalb von vier Monaten (max. 120 Tage) nach 131I-Ablation durchgeführt wurde ohne weitere therapeutische Maßnahmen zwischen Ablation und dxWBS, b) eine zweite dxWBS oder 131I-Therapie (rxWBS), die innerhalb von 1,5 Jahren nach Ablation durchgeführt wurde. Ergebnisse: Bei 25/129 Patienten stimmten die Ergebnisse der initialen und weiteren Scans nicht überein: Bei 15 von 54 Patienten (27%) mit einem positiven initialen dxWBS widersprachen diese Ergebnisse dem zweiten dxWBS oder rxWBS. Neue Läsionen wurden bei 10/74 (14%) Patienten mit einem initial negativen dxWBS entdeckt. Eine Diskordanz zwischen dem ersten und weiteren in der Nachsorge gemessenen stimulierten Tg-Werten wurde in 5/129 (4%) der Patienten gefunden: Bei 2/90 (2%) Patienten mit einer negativen ersten stimulierten Tg-Bestimmung wurde nachfolgend ein positives Ergebnis gefunden. Bei 3/29 (10%) Patienten mit einer positiven ersten Bestimmung wurde bei der zweiten Untersuchung ein negatives Ergebnis festgestellt. Schlussfolgerung: Weniger als vier Monate nach 131I-Ablation ist zu früh für eine diagnostische Radioiod-Ganzkörperszintigraphie mit zeitgleich TSH-stimulierter Tg-Messung. Die Ermittlung des richtigen späteren Zeitpunkts erfordert weitere Untersuchungen.

Das Zeitintervall zwischen 131I Ablation und diagnostischer Ganzkörperszintigraphie bei Patienten mit differenziertem Schilddrüsenkarzinom Weniger als vier Monate nach Ablation dürfte zu früh sein

Patients with high-risk differentiated thyroid cancer have a lower I-131 ablation success rate than low-risk ones in spite of a high ablation activity

OBJECTIVE

To examine success rates in strictly defined high-risk differentiated thyroid cancer (DTC) patients who received a high-activity (≥5550 MBq) adjuvant postoperative I-131 therapy and compare these to the rates found in highest risk and low-risk patients.

DESIGN

Retrospective database study.

PATIENTS

We examined 377 patients with DTC who received I-131 ablation. Patients with distant metastases were classified as very high risk. Patients with primary tumours >4 cm, extensive extrathyroidal invasion (pT4a or pT4b in accordance with the 7th edition of the TNM system), and patients with ≥5 lymph node metastases or any lateral compartment lymph node metastases were considered high risk. All other patients were considered low risk.

MEASUREMENTS

Ablation success rate at first TSH-stimulated follow-up.

RESULTS

The ablation success rate was 72·6% in low-risk patients, 51·7% in high-risk patients and 13·8% in highest risk patients (all differences P < 0·001). In none of the groups, a significant difference in the initial I-131 activity was found between patients with successful and unsuccessful ablation (low risk: P = 0·16, high risk: P = 0·91 and highest risk: P = 0·48). Furthermore, there was no difference in ablation success between patients who received <5550 MBq and those who received ≥5550 Mbq (low risk: P = 0·31, high risk: P = 0·69 and highest risk: P = 0·22).

CONCLUSIONS

Patients with high-risk DTC have a significantly reduced I-131 ablation success rate compared to low-risk ones in spite of high initial I-131 activities. As successful ablation is prognostically important, efforts should be made to improve outcome in these patients.

Reversal of cardiac vagal effects of physostigmine by adjunctive muscarinic blockade

Pre-treatment with reversible acetylcholinesterase (AChE) inhibitors is an effective strategy for reducing lethality following organophosphate nerve agent exposure. AChE inhibition may have unwanted cardiac side effects, which could be negated by adjunctive anti-cholinergic therapy. The aims of the present study were to examine the concentration-dependent effects of physostigmine on cardiac responses to vagus nerve stimulation (VNS), to test whether adjunctive treatment with hyoscine can reverse these effects and to assess the functional interaction and electrophysiological consequences of a combined pre-treatment. Studies were performed in an isolated innervated rabbit heart preparation. The reduction in heart rate with VNS was augmented by physostigmine (1-1000nmol/L), in a concentration-dependent manner - with an EC₅₀ of 19nmol/L. Hyoscine was shown to be effective at blocking the cardiac responses to VNS with an IC₅₀ of 11nmol/L. With concomitant perfusion of physostigmine, the concentration-response curve for hyoscine was shifted downward and to the right, increasing the concentration of hyoscine required to normalise (to control values) the effects of physostigmine on heart rate. At the lowest concentration of hyoscine examined (1nmol/L) a modest potentiation of heart rate response to VNS (+15±3%) was observed. We found no evidence of cardiac dysfunction or severe electrophysiological abnormalities with either physostigmine or hyoscine alone, or as a combined drug-therapy. The main finding of this study is that hyoscine, at concentrations greater than 10^-8M, is effective at reversing the functional effects of physostigmine on the heart. However, low-concentrations of hyoscine may augment cardiac parasympathetic control.

Integrated oxidation membrane filtration process - NOM rejection and membrane fouling

The extent and mechanisms by which organic matter in a solution can be retained and foul a membrane largely depends on the molecular weight of the material being filtered and the molecular weight cut-off (MWCO) of the membrane. The present study investigated the effect of the MWCO of a membrane and the molecular weight distribution of natural organic matter (NOM) in a source water on the increase in resistance to the permeate flux over time. Of particular interest was the effect of oxidation, applied prior to membrane filtration, on the predominant fouling mechanism. Oxidation can change the molecular weight distribution of organic matter in raw water, and therefore the ability of a membrane to retain this organic matter. Oxidation, using both ozonation and UV/H₂O₂, could effectively reduce the extent of fouling for higher MWCO membranes. However, neither oxidation approaches could effectively reduce the extent of fouling for lower MWCO membranes, likely because oxidation could not effectively oxidize lower molecular weight organic matter. Althoug the data indicated that the extent of fouling is increasing with the amount of DOC retained by the membrane, no statistically significant correlation was observed between these parameters. The results suggest that oxidation did not affect the predominant fouling mechanism. However, it did affect the molecular weight distribution of the organic matter retained by the membranes, and as a result, the resistance offered by the foulant cake layer.

Oral pathogens change proliferation properties of oral tumor cells by affecting gene expression of human defensins

The impact of oral pathogens onto the generation and variability of oral tumors has only recently been investigated. To get further insights, oral cancer cells were treated with pathogens and additionally, as a result of this bacterial cellular infection, with human defensins, which are as anti-microbial peptide members of the innate immune system. After cell stimulation, proliferation behavior, expression analysis of oncogenic relevant defensin genes, and effects on EGFR signaling were investigated. The expression of oncogenic relevant anti-microbial peptides was analyzed with real-time PCR and immunohistochemistry. Cell culture experiments were performed to examine cellular impacts caused by stimulation, i.e., altered gene expression, proliferation rate, and EGF receptor-dependent signaling. Incubation of oral tumor cells with an oral pathogen (Porphyromonas gingivalis) and human α-defensins led to an increase in cell proliferation. In contrast, another oral bacterium used, Aggregatibacter actinomycetemcomitans, enhanced cell death. The bacteria and anti-microbial peptides exhibited diverse effects on the transcript levels of oncogenic relevant defensin genes and epidermal growth factor receptor signaling. These two oral pathogens exhibited opposite primary effects on the proliferation behavior of oral tumor cells. Nevertheless, both microbe species led to similar secondary impacts on the proliferation rate by modifying expression levels of oncogenic relevant α-defensin genes. In this respect, oral pathogens exerted multiplying effects on tumor cell proliferation. Additionally, human defensins were shown to differently influence epidermal growth factor receptor signaling, supporting the hypothesis that these anti-microbial peptides serve as ligands of EGFR, thus modifying the proliferation behavior of oral tumor cells.

Test of Electric Charge Conservation with Borexino

Borexino is a liquid scintillation detector located deep underground at the Laboratori Nazionali del Gran Sasso (LNGS, Italy). Thanks to the unmatched radio purity of the scintillator, and to the well understood detector response at low energy, a new limit on the stability of the electron for decay into a neutrino and a single monoenergetic photon was obtained. This new bound, τ≥6.6×10^{28}  yr at 90% C.L., is 2 orders of magnitude better than the previous limit.

Geometrical considerations in cardiac electrophysiology and arrhythmogenesis

The rate of repolarization (RRepol) and so the duration of the cardiac action potential are determined by the balance of inward and outward currents across the cardiac membrane (net ionic current). Plotting action potential duration (APD) as a function of the RRepol reveals an inverse non-linear relationship, arising from the geometric association between these two factors. From the RRepol-APD relationship, it can be observed that a longer action potential will exhibit a greater propensity to shorten, or prolong, for a given change in the RRepol (i.e. net ionic current), when compared with one that is initially shorter. This observation has recently been used to explain why so many interventions that prolong the action potential exert a greater effect at slow rates (reverse rate-dependence). In this article, we will discuss the broader implications of this simple principle and examine how common experimental observations on the electrical behaviour of the myocardium may be explained in terms of the RRepol-APD relationship. An argument is made, with supporting published evidence, that the non-linear relationship between the RRepol and APD is a fundamental, and largely overlooked, property of the myocardium. The RRepol-APD relationship appears to explain why interventions and disease with seemingly disparate mechanisms of action have similar electrophysiological consequences. Furthermore, the RRepol-APD relationship predicts that prolongation of the action potential, by slowing repolarization, will promote conditions of dynamic electrical instability, exacerbating several electrophysiological phenomena associated with arrhythmogenesis, namely, the rate dependence of dispersion of repolarization, APD restitution, and electrical alternans.

Changes to both cardiac metabolism and performance accompany acute reductions in functional capillary supply

BACKGROUND

The relative importance of arteriole supply or ability to switch between substrates to preserve cardiac performance is currently unclear, but may be critically important in conditions such as diabetes.

METHODS

Metabolism of substrates was measured before and after infusion of polystyrene microspheres in the perfused working heart to mimic random capillary loss due to microvascular disease. The effect of acute loss of functional capillary supply on palmitate and glucose metabolism together with function was quantified, and theoretical tissue oxygen distribution calculated from histological samples and ventricular VO(2) estimated.

RESULTS

Microsphere infusion led to a dose-dependent decrease in rate-pressure product (RPP) and oxygen consumption (P<0.001). Microsphere infusion also increased work/unit oxygen consumption of hearts ('efficiency') by 25% (P<0.01). When corrected for cardiac work palmitate oxidation remained tightly coupled to very low workloads (RPP<2500 mmHg/min), illustrating a high degree of metabolic control. Arteriole occlusion by microspheres decreased the density of patent capillaries (P<0.001) and correspondingly increased the average capillary supply area by 40% (P<0.01). Calculated rates of oxygen consumption declined from 16.6±7.2 ml/100 ml/min to 12.4±9 ml/100 ml/min following arteriole occlusion, coupled with increases in size of regions of myocardial hypoxia (Control=22.0% vs. Microspheres=42.2%).

CONCLUSIONS

Cardiac mechanical performance is very sensitive to arteriolar blockade, but metabolite switching from fatty acid to glucose utilisation may also support cardiac function in regions of declining PO(2).

GENERAL SIGNIFICANCE

Preserving functional capillary supply may be critical for maintenance of cardiac function when metabolic flexibility is lost, as in diabetes.

Lifetimes of (214)Po and (212)Po measured with Counting Test Facility at Gran Sasso National Laboratory

The decays of (214)Po into (210)Pb and of (212)Po into (208)Pb tagged by the previous decays from (214)Bi and (212)Bi have been studied inserting quartz vials inside the Counting Test Facility (CTF) at the underground laboratory in Gran Sasso (LNGS). We find that the mean lifetime of (214)Po is (236.00 ± 0.42(stat) ± 0.15(syst)) μs and that of (212)Po is (425.1 ± 0.9(stat) ± 1.2(syst)) ns. Our results are compatible with previous measurements, have a much better signal to background ratio, and reduce the overall uncertainties.

Spinal anesthesia for inguinal hernia repair in infants: a feasible and safe method even in emergency cases

BACKGROUND

Inguinal hernia repair is the most frequently performed surgical procedure in infants and children. Especially in premature infants, prevalence reaches up to 30% in coincidence with high rates of incarceration during the first year of life. These infants carry an increased risk of complications due to general anesthesia. Thus, spinal anesthesia is a topic of growing interest for this group of patients. We hypothesized that spinal anesthesia is a feasible and safe option for inguinal hernia repair in infants even at high risk and cases of incarceration.

METHODS

Between 2003 and 2013, we operated 100 infants younger than 6 months with inguinal hernia. Clinical data were collected prospectively and retrospectively analyzed. Patients were divided into two groups depending on anesthesia procedure (spinal anesthesia, Group 1 vs. general anesthesia, Group 2).

RESULTS

Spinal anesthesia was performed in 69 infants, and 31 infants were operated in general anesthesia, respectively. In 7 of these 31 infants, general anesthesia was chosen because of lumbar puncture failure. Infants operated in spinal anesthesia were significantly smaller (54 ± 4 vs. 57 ± 4 cm; p = 0.001), had a lower body weight (4,047 ± 1,002 vs. 5,327 ± 1,376 g; p < 0.001) and higher rate of prematurity (26 vs. 4%; p = 0.017) compared to those operated in general anesthesia. No complications related to surgery or to anesthesia were found in both groups. The number of relevant preexisting diseases was higher in Group 1 (11 vs. 3%; p = 0.54). Seven of eight emergent incarcerated hernia repairs were performed in spinal anesthesia (p = 0.429).

CONCLUSIONS

Spinal anesthesia is a feasible and safe option for inguinal hernia repair in infants, especially in high-risk premature infants and in cases of hernia incarceration.