The Medical Case for a Positron Emission Tomography and X-ray Computed Tomography Combined Service in Oman

The value of a positron emission tomography and X-ray computed tomography (PET/CT) combined service in terms of diagnostic accuracy, cost-effectiveness and impact on clinical decision-making is welldocumented in the literature. Its role in the management of patients presenting with cancer is shifting from early staging and restaging to the early assessment of the treatment response. Currently, the application of PET/CT has extended to non-oncological specialties—mainly neurology, cardiology and rheumatology. A further emerging application for PET/CT is the imaging of infection/inflammation. This article illustrates some of the PET/CT applications in both oncological and non-oncological disorders. In view of the absence of this modality in Oman, this article aims to increase the awareness of the importance of these imaging modalities and their significant impact on diagnosis and management in both oncological and non-oncological specialties for patients of all age groups as well as the decision-makers

Editorial commentary Hand-held gamma probe or hand-held miniature gamma camera for minimally invasive parathyroidectomy: competition, evolution or synergy?

In this issue of the European Journal of Nuclear Medicine and Molecular Imaging, Joaquin Ortega and co-workers report their pilot experience with a hand-held miniature gamma camera for performing minimally invasive parathyroidectomy (MIP) in five patients with primary hyperparathyroidism (PHPT) most likely caused by a solitary adenoma SPECT can be considered as an essential component of the two scintigraphic procedures that today represent the gold standard for pre-operative imaging of PHPT patients, that is, single-tracer, dual-phase parathyroid scintigraphy with 99m Tc-sestamibi and dual-tracer parathyroid scintigraphy with 99m Tc-sestamibi combined with a thyroidimaging agent (either 123 I-iodide or 99m TcO 4 − ) After imaging of the parathyroid adenoma employing a full diagnostic dose of 99m 99m Tc-sestamibi in the operating suite 10 min before commencing MIP, on a day different from the day on which they performed imagin

Plural metaphysical supervaluationism

It has been argued that quantum mechanics forces us to accept the existence of metaphysical, mind-independent indeterminacy. In this paper we provide an interpretation of the indeterminacy involved in the quantum phenomena in terms of a view that we call Plural Metaphysical Supervaluationism. According to it, quantum indeterminacy is captured in terms of an irreducibly plural relation between the actual world and various misrepresentations of it

Organic Alternatives to Quantum Dots for Intraoperative Near-Infrared Fluorescent Sentinel Lymph Node Mapping:

Intraoperative near-infrared (NIR) fluorescence imaging provides the surgeon with real-time image guidance during cancer and other surgeries. We have previously reported the use of NIR fluorescent quantum dots (QDs) for sentinel lymph node (SLN) mapping. However, because of concerns over potential toxicity, organic alternatives to QDs will be required for initial clinical studies. We describe a family of 800 nm organic heptamethine indocyanine-based contrast agents for SLN mapping spanning a spectrum from 775 Da small molecules to 7 MDa nanocolloids. We provide a detailed characterization of the optical and physical properties of these contrast agents and discuss the advantages and disadvantages of each. We present robust methods for the covalent conjugation, purification, and characterization of proteins with tetra-sulfonated heptamethine indocyanines, including mass spectroscopic site mapping of highly substituted molecules. One contrast agent, NIR fluorescent human serum albumin (HSA800), emerged as the molecule with the best overall performance with respect to entry to lymphatics, flow to the SLN, retention in the SLN, fluorescence yield and reproducibility. This preclinical study, performed on large animals approaching the size of humans, should serve as a foundation for future clinical studies. Mol Imaging (2005) 4, 172 – 181

Time Course of Paclitaxel-Induced Apoptosis in an Experimental Model of Virus-Induced Breast Cancer

Early assessment of the efficacy of treatment is important in patients with breast cancer, whose routine adjuvant regimen frequently includes chemotherapy. Irrespective of the exact mechanisms involved in induction, the common early phenotypic marker of apoptosis is the expression on the outer cell membrane surface of phosphatidylserine, which avidly binds annexin V. 99mTc-labeled annexin V has been proposed for in vivo scintigraphic detection of apoptosis, albeit with contradicting results. This study was performed to define the time course of apoptosis induced by the chemotherapeutic agent paclitaxel in a model of virus-induced murine breast cancer. Methods: The RIII virus induces an estrogen-dependent, slow-growing breast cancer; BALB-c/cRIII female mice with breast tumors averaging 10 mm were studied, both in baseline conditions and at various times after the intravenous administration of paclitaxel (equivalent to a human dose of 20 mg/70 kg of body weight). The biodistribution of 99mTc-annexin V was evaluated at baseline and then at 1, 3, 6, and 24 h after paclitaxel administration. Apoptotic and antiapoptotic markers were also evaluated in tumor samples obtained at the same time points: DNA breaks (terminal deoxynucleotidyl transferase biotin-dUTP nick-end labeling [TUNEL]), active caspase-3, apoptosis-inducing factor, and Bcl-2 protein. Results: Baseline uptake of 99mTc-annexin V in breast tumors was about 2-fold higher than the uptake in normal breast tissue (demonstrating some ongoing apoptosis); tracer uptake increased at 1 and 3 h after paclitaxel administration (to almost double the baseline value) and then declined to levels even lower than baseline. Although no activation of the apoptosis-inducing factor mechanism was detected, a peak in TUNEL-positive tumor cells was reached 3 h after paclitaxel administration (to more than 6-fold the baseline level). The antiapoptotic marker Bcl-2 exhibited a biphasic pattern, with a maximum drop at 3 h, followed by return toward baseline levels at 6 h. Conclusion: These results define the time course of various biologic events taking place in this model of murine breast cancer after a proapoptotic insult (single-dose paclitaxel). Although confirming that in vivo uptake of 99mTc-annexin V reflects the degree of apoptosis, the study also suggests that the apoptotic response to antitumor therapy may differ from tumor type to tumor type. Therefore, contradicting results previously reported may depend on an inadequate time window chosen for imaging with 99mTc-annexin V

A new severity score index for phenotypic classification and evaluation of responses to treatment in type I Gaucher disease

Gaucher disease is the first lysosomal storage disease for which specific therapy became available. Over 4800 patients have been treated with enzyme replacement therapy. Analysis of Gaucher disease registry data has outlined the clinical heterogeneity of the disease and the different responses to treatment from patient to patient, and for different organs. This variability in clinical response justifies the development of a severity score index to assess disease activity, stage and prognosis, and to quantify the effects of treatment.The \u201cGaucher Disease Severity Score Index Type I\u201d(GauSSI-I), is based on the clinical experience of the authors and an extensive literature review, including data from the International Gaucher Registry. In particular for skeletal disease, all the available scoring systems have been reviewed and compared in order to provide a skeletal scoring system that allows use of any of the different methods. Siix specific domains, in which different items were scored according to their impact on morbidity, were characterized. GauSSI-I was evaluated in 53 type I Gaucher patients treated with imiglucerase, and it was compared to the Zimran score, the only severity index score so far available. It is a reliable method for staging the severity of adult type I Gaucher disease, and it is more sensitive than the Zimran score for monitoring the response to treatment

PRNP P39L variant is a rare cause of frontotemporal dementia in Iialian population

The missense P39L variant in the prion protein gene (PRNP) has recently been associated with frontotemporal dementia (FTD). Here, we analyzed the presence of the P39L variant in 761 patients with FTD and 719 controls and found a single carrier among patients. The patient was a 67-year-old male, with a positive family history for dementia, who developed apathy, short term memory deficit, and postural instability at 66. Clinical and instrumental workup excluded prion disease. At MRI, bilateral frontal lobe atrophy was present. A diagnosis of FTD was made, with a mainly apathetic phenotype. The PRNP P39L mutation may be an extremely rare cause of FTD (0.13%)

All is fish that comes to the net: metabarcoding for rapid fisheries catch assessment

Monitoring marine resource exploitation is a key activity in fisheries science and biodiversity conservation. Since research surveys are time‐consuming and costly, fishery‐dependent data (i.e. derived directly from fishing vessels) are increasingly credited with a key role in expanding the reach of ocean monitoring. Fishing vessels may be seen as widely ranging data‐collecting platforms, which could act as a fleet of sentinels for monitoring marine life, in particular exploited stocks. Here, we investigate the possibility of assessing catch composition of single hauls carried out by trawlers by applying DNA metabarcoding to the dense water draining from fishing nets just after the end of hauling operations (hereafter ‘slush’). We assess the performance of this approach in portraying β‐diversity and examining the quantitative relationship between species abundances in the catch and DNA amount in the slush (read counts generated by amplicon sequencing). We demonstrate that the assemblages identified using DNA in the slush satisfactorily mirror those returned by visual inspection of net content (about 71% of species and 86% of families of fish) and detect a strong relationship between read counts and species abundances in the catch. We therefore argue that this approach could be upscaled to serve as a powerful source of information on the structure of demersal assemblages and the impact of fisheries

Feasibility and long-term results of focused radioguided parathyroidectomy using a "low" 37 MBq (1 mCi) (99m)Tc-sestamibi protocol

Aim of the present study was to investigate the feasibility and long-term results of focused radioguided parathyroidectomy using a "low" 37 MBq (1 mCi) (99m)Tc-sestamibi dose protocol compared to conventional "high 740 MBq (20 mCi) (99m)Tc-sestamibi dose protocol" in patients with primary hyperparathyroidism (PHPT). The data of focused radioguided surgery obtained in a group of 320 consecutive PHPT patients with high probability of the presence of a solitary parathyroid adenoma (PA) were studied. All patients underwent preoperative imaging work-up of double-tracer (99m)Tc-pertechnetate/(99m)Tc-sestamibi subtraction parathyroid scintigraphy (Sestamibi scintigraphy) and high resolution neck ultrasound (US). In 301/320 patients (96.6%) focused minimally invasive radioguided surgery was successfully performed by administering a "low" 37 MBq (1 mCi) (99m)Tc-sestamibi dose in the operating room 10 minutes before operation. No major intraoperative complications were recorded. Focused radioguided surgery required a mean time of 32 min and a mean hospital stay of 1.2 days. Local anesthesia was applied in 75 patients, 66 of whom (88%) were patients older than 65 years with comorbidities contraindicating general anesthesia. No case of persistent or recurrent PHPT was observed during post-surgical follow-up (range = 18–70 months; mean +/- SD = 15.3 +/- 9.1 months). Radiation exposure dose to the operating surgeon was 1.2 μSi/hour with the "low 37 MBq (1 mCi) (99m)Tc-sestamibi dose", and less than 1.0 μSi/hour for the other operating-room personnel. Focused low dose radioguided parathyroidectomy is a safe and effective means to localize parathyroid adenomas in patients affected by solitary PA thus reducing by 20 fold the radiation exposure dose to the patients and operating room personnel