Enzyme-based chemical biosensors are based on biological recognition. In order to operate, the enzymes must be available to catalyze a specific biochemical reaction and be stable under the normal operating conditions of the biosensor. Design of biosensors is based on knowledge about the target analyte, as well as the complexity of the matrix in which the analyte has to be quantified. This article reviews the problems resulting from the interaction of enzyme-based amperometric biosensors with complex biological matrices containing the target analyte(s). One of the most challenging disadvantages of amperometric enzyme-based biosensor detection is signal reduction from fouling agents and interference from chemicals present in the sample matrix. This article, therefore, investigates the principles of functioning of enzymatic biosensors, their analytical performance over time and the strategies used to optimize their performance. Moreover, the composition of biological fluids as a function of their interaction with biosensing will be presented.

Planar 131 I scintigraphy is routinely used to detect radioiodineavid metastases of differentiated thyroid carcinoma (DTC). However, the modality has limitations, such as low sensitivity and lack of anatomic landmarks. We investigated whether SPECT with integrated low-dose CT may have additional value over planar imaging in detecting residue and metastases in DTC patients. Methods: We studied 117 consecutive thyroidectomized DTC patients. On 2 different hybrid dual-head g-cameras (55 patients on one camera and 62 on the other), 108 patients underwent 131 I diagnostic imaging and SPECT/ CT, and 9 underwent posttherapeutic 131 I planar imaging and SPECT/CT. We assigned an incremental value to SPECT/CT when it provided better identification and interpretation of the foci of radioiodine uptake, more correct anatomic localization and characterization, and precise differentiation between tumor lesions and physiologic uptake. Results: Planar imaging showed 116 foci of uptake in 52 of 117 patients, and SPECT/CT showed 158 foci in 59 of 117 patients, confirming all foci seen on planar imaging but identifying an additional 28 occult foci in 10 of 52 patients. Fourteen occult foci were shown on SPECT/CT in 7 further patients whose planar imaging findings were negative. SPECT/ CT correctly characterized 48 foci unclear on planar imaging, also defining location and extent. SPECT/CT was a determinant in classifying as neoplastic those foci for which planar imaging seemed to exclude malignancy, discriminating between residue and lymph node metastases in the neck, some of which were adjacent to salivary glands and had been missed on planar imaging. SPECT/CT also showed occult lesions in the mediastinum, abdomen, and pelvis and identified small bone metastases unsuspected on planar imaging. Globally, SPECT/CT had an incremental value over planar imaging in 67.8% of patients, modified therapeutic management in 35.6% of positive cases, and avoided unnecessary treatment in 20.3% of patients with only single benign lesions or physiologic uptake. Conclusion: 131 I SPECT/CT improved planar data interpretation, showing a higher number of DTC lesions, more precisely localizing and characterizing DTC foci, and more correctly differentiating between physiologic uptake and metastases, thus permitting the most appropriate therapeutic approach to be chosen. A wider use of this method is suggested complementary to planar imaging in selected DTC patients. Convent ional planar 131 I whole-body scintigraphy, in association with serum thyroglobulin measurement, is still considered the routine diagnostic procedure in patients with well-differentiated thyroid carcinoma (DTC). This modality is used in the detection of both thyroid tissue residue and local and distant metastases, after thyroidectomy for staging and after radioiodine ablation for restaging and long-term follow-up (1). A sensitivity of 45%275% and a specificity of 90%2100% have been reported in the literature for diagnostic planar 131 I whole-body imaging in detecting recurrences or me...

HAART, particularly stavudine, is associated with a high prevalence of subclinical hypothyroidism. Hypotheses are made regarding responsible mechanisms and risk factors. Thyroid function should be tested and sequentially rechecked in HAART patients.

Cholangiocarcinoma (CCA) is a highly-aggressive malignancy arising from the biliary tree, characterized by a steady increase in incidence globally and a high mortality rate. Most CCAs are diagnosed in the advanced and metastatic phases of the disease, due to the paucity of signs and symptoms in the early stages. This fact, along with the poor results of the local and systemic therapies currently employed, is responsible for the poor outcome of CCA patients and strongly supports the need for novel therapeutic agents and strategies. In recent years, the introduction of next-generation sequencing technologies has opened new horizons for a better understanding of the genetic pathophysiology of CCA and, consequently, for the identification and evaluation of new treatments tailored to the molecular features or alterations progressively elucidated. In this review article, we describe the potential targets under investigation and the current molecular therapies employed in biliary tract cancers. In addition, we summarize the main drugs against CCA under evaluation in ongoing trials and describe the preliminary data coming from these pioneering studies.

No abstract