2013 European thyroid association guidelines for cervical ultrasound scan and ultrasound-guided techniques in the postoperative management of patients with thyroid cancer

Cervical ultrasound scanning (US) is considered a key examination, by all major thyroid and endocrine specialist societies for the postoperative follow-up of thyroid cancer patients to assess the risk of recurrence. Neck US imaging is readily available, non-invasive, relatively easy to perform, cost-effective, and can guide diagnostic and therapeutic procedures with low complication rates. Its main shortcoming is its operator-dependency. Because of the pivotal role of US in the care of thyroid cancer patients, the European Thyroid Association convened a panel of international experts to review technical aspects, indications, results, and limitations of cervical US in the initial staging and follow-up of thyroid cancer patients. The main aim is to establish guidelines for both a cervical US scanning protocol and US-guided diagnostic and therapeutic procedures in patients with thyroid cancer. This report presents (1) standardization of the US scanning procedure, techniques of US-guided fine-needle aspiration, and reporting of findings; (2) definition of criteria for classification of malignancy risk based on cervical US imaging characteristics of neck masses and lymph nodes; (3) indications for US-guided fine-needle aspiration and for biological in situ assessments; (4) proposal of an algorithm for the follow-up of thyroid cancer patients based on risk stratification following histopathological and cervical US findings, and (5) discussion of the potential use of US-guided localization and ablation techniques for locoregional thyroid metastases.

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.

A genome-wide screen in 1119 relative pairs with autoimmune thyroid disease

CONTEXT

Autoimmune thyroid diseases (AITD), comprising Graves' disease and autoimmune hypothyroidism, are characterized by loss of immunological self-tolerance to thyroid antigens. These are complex diseases arising from a combination of genetic and environmental factors. An understanding of the genetic susceptibility factors for AITD could help to target treatments more effectively and identify people at risk for these conditions.

OBJECTIVE

The objective of this study was to identify regions of genetic linkage to AITD that could potentially harbor genetic susceptibility factors for these conditions.

DESIGN

The study design was a genome-wide screen performed on affected relative pairs with AITD.

SETTING

Patients were recruited through hospital endocrinology clinics.

PARTICIPANTS

Some 1119 Caucasian relative pairs affected with AITD (Graves' disease or autoimmune hypothyroidism) were recruited into the study.

INTERVENTION

Blood samples were obtained from each participant for DNA analysis, and clinical questionnaires were completed.

MAIN OUTCOME MEASURE

The study aimed to identify regions of genetic linkage to AITD.

RESULTS

Three regions of suggestive linkage were obtained on chromosomes 18p11 (maximum LOD score, 2.5), 2q36 (maximum LOD score, 2.2), and 11p15 (maximum LOD score, 2.0). No linkage to human leukocyte antigen was found.

CONCLUSIONS

The absence of significant evidence of linkage at any one locus in such a large dataset argues that genetic susceptibility to AITD reflects a number of loci, each with a modest effect. Linkage analysis may be limited in defining such loci, and large-scale association studies may prove to be more useful in identifying genetic susceptibility factors for AITD.

High prevalence of autoantibodies among Danish centenarians

The aim of this study was to investigate the prevalence of organ and nonorgan specific autoantibodies in relation to disability and comorbidity in an unselected population of centenarians. A population-based survey of all persons living in Denmark who celebrated their 100th birthday during the period 1 April 1995 to 31 May 1996, a total of 276 persons, was undertaken. Participants underwent an interview, a physical examination and blood sampling. Organ specific autoantibodies (Tg-ab, TPO-ab, PCA-ab) and nonorgan specific autoantibodies (ANA, IgM RF, IgA RF, MPO-ab, c-ANCA, p-ANCA, oxLDL-ab, IgM ACA, IgG ACA, PR3-ANCA, histone-ab, SSA-ab, SSB-ab, Mit-ab) were measured, and comorbidity and disability (Katz Index of ADL) were registered. In all, 207 (75.0%) of 276 eligible subjects participated, and 148 agreed to blood tests. A large majority (79.3%) had at least one autoantibody detected. Organ specific autoantibodies were present in 32.1% of the centenarians. The high level of autoantibodies did not reflect an equally high level of overt autoimmune disease. While nonorgan specific autoantibodies were equally represented in less-disabled/disabled subjects as well as in subjects with low/high comorbidity, significantly fewer subjects with organ specific autoantibodies were found among less-disabled subjects or subjects with low comorbidity. Autoantibodies (both nonorgan and organ specific) are common in an unselected population of centenarians of today, but do not reflect an equally high level of overt autoimmune disease. Non-organ specific autoantibodies are evenly distributed irrespective of the level of disability or comorbidity, suggesting underlying, undiagnosed pathological processes which may be part of the processes involved in frailty.

Reversed-phase high-performance liquid chromatographic determination of the new antitumor agent cyclopentenyl cytosine in biological fluids

Cyclopentenyl cytosine (CPE-C) is a synthetic carbocyclic nucleoside that possesses diverse antitumor and antiviral activity. CPE-C has been studied extensively at the preclinical level and has been evaluated in a Phase I clinical trial involving patients with solid tumors. A narrow-bore, reversed-phase HPLC method that has been developed for the sensitive measurement of CPE-C in plasma and urine in order to carry out these studies is described. Covalent solid-phase extraction based on an immobilized phenylboronic acid ligand is employed to isolate both CPE-C and endogenous ribonucleosides from the biological matrix selectively and efficiently. This is followed by isocratic elution of the extract with pH 5.0, 0.1 M ammonium formate buffer at 0.150 ml/min on a tandem, switchable, C18 narrow-bore (2.1 mm I.D.) column system in which the precolumn is automatically backflushed to eliminate late-eluting components. UV detection at 278 nm provides a limit of quantitation of 0.1 microM for CPE-C in rat and human plasma with a precision better than 4% for the range 1-20 microM in rat plasma. Application of this assay to the determination of the bolus dose plasma kinetics and disposition of 2 mg/kg CPE-C in rats is illustrated. This method is amenable to partial automation and is well-suited for the analysis of clinical samples.

Clinical pharmacokinetics of physostigmine in patients with Alzheimer's disease

OBJECTIVE

To study the pharmacokinetic and pharmacodynamic properties of physostigmine in subjects with Alzheimer's disease.

METHODS

Plasma physostigmine concentration and butyrylcholinesterase inhibition were measured in blood samples collected during and after a single high-dose (1 to 1.5 mg for 45 to 60 minutes) and a sustained low-dose steady-state intravenous infusion in nine subjects with Alzheimer's disease. Escalating doses (0.5 to 25 mg/day) were administered during a 2-week period. A dose (2 to 12 mg/day) that optimized cognition in each subject was identified and then administered in a randomized, double-blind, placebo-controlled crossover design for 1 week.

RESULTS

The elimination half-life of physostigmine was 16.4 +/- 3.2 (SE) minutes. Clearance and volume of distribution were 7.7 +/- 0.9 (SE) L/min and 2.4 +/- 0.6 (SE) L/kg, respectively. Butyrylcholinesterase inhibition half-life was 83.7 +/- 5.2 (SE) minutes. During sustained steady-state infusion, plasma physostigmine concentration (r = 0.95) and butyrylcholinesterase inhibition (r = 0.99) were linearly correlated with the dose. In five cognitive responders, the memory enhancement was significantly correlated (r = 0.86; p < 0.05) with butyrylcholinesterase inhibition.

CONCLUSIONS

These results showed that, in cognitive responders, memory enhancement by physostigmine in Alzheimer's disease is correlated directly to the magnitude of plasma cholinesterase inhibition. Furthermore, during single-dose conditions, the dynamic half-life is five-fold longer than the kinetic half-life.

Rapid brain uptake of manganese(II) across the blood-brain barrier

54Mn2+ uptake into brain and choroid plexus from the circulation was studied using the in situ rat brain perfusion technique. Initial uptake from blood was linear with time (30 s to 6 min) and extrapolated to zero with an average transfer coefficient of approximately 6 x 10(-5) ml/s/g for brain and approximately 7 x 10(-3) ml/s/g for choroid plexus. Influx from physiologic saline was three- to fourfold more rapid and exceeded that predicted for passive diffusion by more than one order of magnitude. The lower uptake rate from blood could be explained by plasma protein binding as the free fraction of 54Mn2+ in rat plasma was < or = 30%. Purified albumin, transferrin, and alpha 2-macroglobulin were each found to bind 54Mn2+ significantly and to restrict brain 54Mn2+ influx. The results demonstrate that 54Mn2+ is readily taken up into the CNS, most likely as the free ion, and that transport is critically affected by plasma protein binding. The results support the hypothesis that Mn2+ transport across the blood-brain barrier is facilitated by either an active or a passive mechanism.

Electron-impact and chemical ionization detection of nicotine and cotinine by gas chromatography-mass spectrometry in rat plasma and brain

Nicotine and its metabolite, cotinine, were measured in rat plasma and brain by gas chromatography-mass spectrometry. Both agents were extracted from plasma and brain, separated on a capillary column, and quantified by single-ion monitoring. The major fragment ions of nicotine and cotinine at m/z 84 and m/z 98, respectively, were monitored by electron-impact ionization detection and the protonated molecular ions at m/z 163 and m/z 177, respectively, were monitored by chemical ionization detection. Both compounds were quantified using deuterium-labeled nicotine and cotinine, respectively, as internal standards.

Cyclopentenyl cytosine: interspecies predictions based on rodent plasma and urine kinetics

A hybrid compartmental-physiological model for cyclopentenyl cytosine (CPE-C) is designed on the basis of early limited rodent pharmacokinetic data. Application of model independent pharmacokinetics and biochemical knowledge was first used to conceptualize such a model. The approach was to scale the physiological parameters of the model (compartmental clearances) and keep constant the anatomic parameters of the model (compartment volumes). Scaling of physiological mechanisms was based on body weight/surface area ratios. Using these principles, simulations with the model can reasonably anticipate the in vivo behavior of (CPE-C) in several species (mouse, rat, dog). The model is useful in understanding species differences in pharmacokinetic behavior of CPE-C.

Pharmacokinetics and metabolism of cyclopentenyl cytosine in nonhuman primates

The plasma and cerebrospinal fluid pharmacokinetics of cyclopentenyl cytosine (CPE-C) were studied following i.v. bolus and continuous i.v. infusion in male rhesus monkeys. Following an i.v. bolus dose of 100 mg/m2 plasma elimination of CPE-C was biexponential with a mean t1/2 alpha of 8.4 min, a mean t1/2 beta of 36 min, and a total clearance (CLTB) of 662 ml/min/m2, which is 5- to 10-fold higher than clearance rates in rodents and dogs. Less than 20% of the total dose of CPE-C was excreted unchanged in the urine. The remainder was excreted as the inactive deamination product cyclopentenyl uridine (CPE-U). The ratio of the areas under the plasma concentration versus time curves of CPE-U to CPE-C was 7.0 +/- 2.4 following i.v. bolus CPE-C. The cerebrospinal fluid:plasma ratios of CPE-C and CPE-U were 0.08 and 0.30, respectively. Continuous i.v. infusion of CPE-C was compared to continuous infusion of 1-beta-D-arabinofuranosylcytosine in two monkeys. Steady state plasma concentrations, normalized to a dose of 12.5 mg/m2/h of CPE-C and an equimolar dose of 1-beta-D-arabinofuranosylcytosine, were 2.1 and 0.53 microM, respectively. The steady state concentrations of their corresponding uridine metabolites (CPE-U and 1-beta-D-arabinofuranosyluridine) were 8.2 and 15.5 microM. The rapid elimination of CPE-C by deamination in the primate resulted in a much higher CLTB and considerably lower total drug exposure than in rodents and dogs that clear CPE-C at a much lower rate by renal excretion. These significant interspecies differences in the disposition of CPE-C should be considered in the selection of a starting dose and schedule for human trials and suggest that a pharmacologically directed dose escalation scheme should be used in the planned phase I studies.

Metabolism of 1,1,1,2,2-pentafluorohexane and 1,1-difluorocyclohexane by rat liver microsomes in vitro

Metabolism of 1,1,1,2,2-pentafluorohexane with liver microsomes from phenobarbital-treated rats gave only one metabolite, namely, the 5-hydroxy derivative. Under similar conditions 1,1-difluorocyclohexane was metabolized to give mainly the 3- and 4-hydroxy derivatives in the ratio 1: approximately 5.5. The structures of these metabolites were established by chemical ionization (CI) and/or electron impact (EI) mass spectrometry and confirmed by synthesis in the case of 1,1-difluorocyclohexan-4-ol. Oxidation of 1,1-difluorocyclohexane with lead tetrakis(trifluoroacetate) also gave, inter alia, the 3- and 4-hydroxy derivatives. In saturated hydrocarbons complete replacement of hydrogen by fluorine at one particular carbon will not only block microsomal hydroxylation thereat but will also inhibit hydroxylation at neighbouring hydrogen-bearing carbons, (alpha almost completely, beta markedly, gamma slightly).