PURPOSE 53BP1 foci detection in peripheral blood lymphocytes (PBLs) by immunofluorescence microscopy (IFM) is a sensitive and quantifiable DNA double-strand break (DSB) marker. In addition, high-resolution transmission electron microscopy (TEM) with immunogold labeling of 53BP1 and DSB-bound phosphorylated Ku70 (pKu70) can be used to determine the progression of the DNA repair process. To establish this TEM method in the PBLs of patients with cancer, we analyzed and characterized whether different modes of irradiation influence the formation of DSBs, and whether accompanying chemotherapy influences DSB formation. METHODS We obtained 86 blood samples before and 0.1, 0.5, and 24 h after irradiation from patients (n = 9) with head and neck or rectal cancers receiving radiotherapy (RT; n = 4) or radiochemotherapy (RCT; n = 5). 53BP1 foci were quantified by IFM. In addition, TEM was used to quantify gold-labelled pKu70 dimers and 53BP1 clusters within euchromatin and heterochromatin of PBLs. RESULTS IFM analyses ss a DSB may be indicated by a 53BP1 focus but not every 53BP1 focus represents a DSB.PURPOSE Merkel cell carcinoma is highly sensitive to both radiation and immunotherapy. Moreover, concurrent radioimmunotherapy may capitalize on anti-tumor immune activity and improve Merkel cell treatment response, although an enhanced immune system may cross-react with native tissues and lead to significant sequelae.  https://www.selleckchem.com/products/17-AAG(Geldanamycin).html  METHODS Here we present a case study of a patient with metastatic Merkel cell carcinoma treated with radiotherapy concurrent with pembrolizumab. RESULTS After radioimmunotherapy, the patient developed sensory neuropathy, visual hallucinations, and mixed motor neuron findings. Neurologic dysfunction progressed to profound gastrointestinal dysmotility necessitating parenteral nutrition and intubation with eventual expiration. CONCLUSION This case represents a unique autoimmune paraneoplastic neurologic syndrome, likely specific to neuroendocrine tumors and motivated by concurrent radioimmunotherapy. Recognition of the potential role of radioimmunotherapy may provide an advantage in anticipating these severe sequelae.BACKGROUND There is no consensus as to when surgical intervention should be considered for recurrent ileocolic intussusceptions in a stable patient after previous successful air contrast enema. OBJECTIVE To review the patterns of ileocolic intussusceptions, air contrast enema success rates, and pathologic lead point rates in patients with and without recurrence to evaluate whether treatment outcomes depend on the number and timing between episodes. MATERIALS AND METHODS We retrospectively reviewed 683 children with air contrast enema performed for ileocolic intussusception between January 2000 and May 2018. Recurrent intussusceptions were separated into mutually exclusive categories short-term only (≤7 days between episodes) and long-term (>7 days between episodes) intussusceptions. Long-term recurrences included both long-term only and long- and short-term intussusceptions. RESULTS Of the 683 patients, 606 (89%) had at least 1 successful air contrast enema. Of the 606, 115 (19%) had recurrent intussusceptiontimes, potentially precluding the need for surgical intervention.Fatty acids are a major source of structural diversity within the lipidome due to variations in their acyl chain lengths, branching, and cyclization, as well as the number, position, and stereochemistry of double bonds within their mono- and poly-unsaturated species. Here, the utility of 193 nm UltraViolet PhotoDissociation tandem mass spectrometry (UVPD-MS/MS) has been evaluated for the detailed structural characterization of a series of unsaturated fatty acid lipid species. UVPD-MS/MS of unsaturated fatty acids is shown to yield pairs of unique diagnostic product ions resulting from cleavages adjacent to their C=C double bonds, enabling unambiguous localization of the site(s) of unsaturation within these lipids. The effect of several experimental variables on the observed fragmentation behaviour and UVPD-MS/MS efficiency, including the position and number of double bonds, the effect of conjugated versus non-conjugated double bonds, the number of laser pulses, and the influence of alkali metal cations (Li, Na, K) as the ionizing adducts, has been evaluated. Importantly, the abundance of the diagnostic ions is shown to enable relative quantitation of mixtures of fatty acid isomers across a range of molar ratios. Finally, the practical application of 193 nm UVPD-MS/MS is demonstrated via characterization of changes in the ratios of fatty acid double bond positional isomers in isogenic colorectal cancer cell lines. This study therefore demonstrates the practicality of UVPD-MS/MS for the structural characterization of fatty acid isomers in lipidome analysis workflows.Optical sensors are prepared by reduction of gold ions using freshly etched hydride-terminated porous silicon, and their ability to specifically detect binding between protein A/rabbit IgG and asialofetuin/Erythrina cristagalli lectin is studied. The fabrication process is simple, fast, and reproducible, and does not require complicated lab equipment. The resulting nanostructured gold layer on silicon shows an optical response in the visible range based on the excitation of localized surface plasmon resonance. Variations in the refractive index of the surrounding medium result in a color change of the sensor which can be observed by the naked eye. By monitoring the spectral position of the localized surface plasmon resonance using reflectance spectroscopy, a bulk sensitivity of 296 nm ± 3 nm/RIU is determined. Furthermore, selectivity to target analytes is conferred to the sensor through functionalization of its surface with appropriate capture probes. For this purpose, biomolecules are deposited either by physical adsorption or by covalent coupling. Both strategies are successfully tested, i.e., the optical response of the sensor is dependent on the concentration of respective target analyte in the solution facilitating the determination of equilibrium dissociation constants for protein A/rabbit IgG as well as asialofetuin/Erythrina cristagalli lectin which are in accordance with reported values in literature. These results demonstrate the potential of the developed optical sensor for cost-efficient biosensor applications. Graphical abstract.