An Overview of In Vitro Assays of 64Cu-, 68Ga-, 125I-, and 99mTc-Labelled Radiopharmaceuticals Using Radiometric Counters in the Era of Radiotheranostics.

Radionuclides are unstable isotopes that mainly emit alpha (α), beta (ß) or gamma (γ) radiation through radiation decay. Therefore, they are used in the biomedical field to label biomolecules or drugs for diagnostic imaging applications, such as positron emission tomography (PET) and/or single-photon emission computed tomography (SPECT). A growing field of research is the development of new radiopharmaceuticals for use in cancer treatments. Preclinical studies are the gold standard for translational research. Specifically, in vitro radiopharmaceutical studies are based on the use of radiopharmaceuticals directly on cells. To date, radiometric ß- and γ-counters are the only tools able to assess a preclinical in vitro assay with the aim of estimating uptake, retention, and release parameters, including time- and dose-dependent cytotoxicity and kinetic parameters. This review has been designed for researchers, such as biologists and biotechnologists, who would like to approach the radiobiology field and conduct in vitro assays for cellular radioactivity evaluations using radiometric counters. To demonstrate the importance of in vitro radiopharmaceutical assays using radiometric counters with a view to radiogenomics, many studies based on 64Cu-, 68Ga-, 125I-, and 99mTc-labeled radiopharmaceuticals have been revised and summarized in this manuscript.

COVID-19 safety measures at the Radiology Unit of a Transplant Institute: the non-COVID-19 patient's confidence with safety procedures.

PURPOSE: To support the wellbeing of both patients and their families, our aim was to investigate the satisfaction of non-COVID in- and out-patients regarding safety measures implemented at our radiology unit of a transplant institute against COVID infection. MATERIALS AND METHODS: Over a five-month period, adult patients' feedback was obtained by a questionnaire on the fear of contracting COVID-19 during a radiology examination, the perceived delay in treatment, and the following safety measures implemented: modified schedules to limit the number of patients in the waiting area and to maximize social distancing; assistance by staff when visitors were not admitted; cleaning and disinfection of machines; mask wearing and hand hygiene of staff; and staff advice on hand hygiene and infection control precautions. RESULTS: Over a five-month period, our preliminary results (387 patients) showed general patient satisfaction (99.1%) with safety measures applied at our radiology unit. Patients were satisfied with distancing and assistance by staff (100%), cleaning and disinfection (91%), mask wearing and hand hygiene of the staff (97%), and staff advice (94%). There was some criticism of the perceived delay in treatment (7.3%) and in the scheduling of the waiting list (5.4%), with 5.4% fearing contracting the virus. Patients' awareness of safety measures and confidence in the hospital preparedness policy was perceived by all interviewers, and 100% appreciated being questioned. CONCLUSION: The feedback given by the non-COVID patient helps to measure the quality in health care, to improve the quality service, and to protect and satisfy more vulnerable patients, also during the COVID-19 pandemic.

OCCUPATIONAL RADIATION DOSE PERFORMING HEPATOBILIARY MINIMALLY INVASIVE PROCEDURES IN CHILDREN WEIGHING LESS THAN 20 kg.

Our objective is to retrospectively evaluate the effective dose (E) of operators performing pediatric Hepatobiliary Minimally Invasive Procedures (HMIP). Between October 2015 and December 2017, 58 consecutive HMIP were performed on 26 children weighing less than 20 kg (mean 12.3 kg, median 13 kg, range 2.4-20 kg). About 31 vascular procedures (n = 9 hepatic venograms with/without stenting; n = 9 retrograde wedge portography; n = 8 transhepatic portography with angioplasty and/or stenting and n = 5 hepatic arteriography/embolization) and 27 non-vascular procedures (n = 6 percutaneous transhepatic biliary drainage (PTBD); n = 3 bilioplasty; n = 15 biliary catheter change and n = 3 cholangiogram) were performed. Electronic personal dosimeters were used to measure radiation doses to the interventional radiologist, radiographer and anesthesia nurse. The results shows the highest mean effective dose: interventional radiologist's in PTBD (1.18 µSv); radiographer's in hepatic veins phlebography with/without stenting (0.25 µSv) and nurse's in hepatic arteriography/embolization (0.26 µSv). Operators' E can vary depending on the complexity of procedure performed and the position of the operators within the angiosuite.

A possible relativistic jetted outburst from a massive black hole fed by a tidally disrupted star.

Gas accretion onto some massive black holes (MBHs) at the centers of galaxies actively powers luminous emission, but most MBHs are considered dormant. Occasionally, a star passing too near an MBH is torn apart by gravitational forces, leading to a bright tidal disruption flare (TDF). Although the high-energy transient Sw 1644+57 initially displayed none of the theoretically anticipated (nor previously observed) TDF characteristics, we show that observations suggest a sudden accretion event onto a central MBH of mass about 10(6) to 10(7) solar masses. There is evidence for a mildly relativistic outflow, jet collimation, and a spectrum characterized by synchrotron and inverse Compton processes; this leads to a natural analogy of Sw 1644+57 to a temporary smaller-scale blazar.

Adenine phosphoribosyltransferase (APRT) deficiency: a new genetic mutation with early recurrent renal stone disease in kidney transplantation.

Adenine phosphoribosyltransferase (APRT) deficiency, a rare inborn error inherited as an autosomic recessive trait, presents with 2,8-dihydroxyadenine (2,8-DHA) crystal nephropathy. We describe clinical, biochemical and molecular findings in a renal transplant recipient with renal failure, 2,8-DHA stones and no measurable erythrocyte APRT activity. Homozygous C > G substitution at -3 in the splicing site of exon 2 (IVS2 -3 c > g) was found in the APRT gene. The patient's asymptomatic brother was heterozygous for such mutation, and his APRT activity was 23% of controls. A splicing alteration leading to incorrect gene transcription and virtually absent APRT activity is seemingly associated with the newly identified mutation.