10 research outputs found
LaBr3:Ce scintillation gamma camera prototype for X and gamma ray imaging
88Re is a beta and gamma emitter used in metabolic radiotherapy. SCINTIRAD is a multidisciplinary collaboration that aims at determining the radio-response of 188Re in cells \u201cin vitro\u201d and the biodistribution in different organs of mice \u201cin vivo\u201d, and studying the therapeutic effect on liver and other tumours induced in mice. Several tumour cell lines have been treated \u201cin vitro\u201d with a 188Re solution. The dosimetry of 188Re used to target the different lines of cancer cells has been evaluated using GEANT4, and preliminary results are presented. Studies to optimize the imaging of 188Re \u201cin vivo\u201d have also continued, including the characterization of H8500 Flat Panel PMT and of LaBr3 crystals, and the development of dedicated electronics
SIMULATIONS AND TESTS FOR METABOLIC RADIOTHERAPY WITH 188RE
188Re is a beta and gamma emitter used in metabolic radiotherapy. SCINTIRAD is a multidisciplinary collaboration that aims at determining the radio-response of 188Re in cells \u201cin vitro\u201d and the biodistribution in different organs of mice \u201cin vivo\u201d, and studying the therapeutic effect on liver and other tumours induced in mice. Several tumour cell lines have been treated \u201cin vitro\u201d with a 188Re solution. The dosimetry of 188Re used to target the different lines of cancer cells has been evaluated using GEANT4, and preliminary results are presented. Studies to optimize the imaging of 188Re \u201cin vivo\u201d have also continued, including the characterization of H8500 Flat Panel PMT and of LaBr3 crystals, and the development of dedicated electronics
Simulations and tests for metabolic radiotherapy with Re-188
Re-188 is a beta and gamma emitter used in metabolic radiotherapy. SCINTIRAD is a multidisciplinary collaboration that aims at determining the radio-response of Re-188 in cells "in vitro" and the biodistribution in different organs of mice "in vivo", and studying the therapeutic effect on liver and other tumours induced in mice. Several tumour cell lines have been treated "in vitro" with a Re-188 solution. The dosimetry of Re-188 used to target the different lines of cancer cells has been evaluated using GEANT4, and preliminary results are presented. Studies to optimize the imaging of Re-188 "in vivo" have also continued, including the characterization of H8500 Flat Panel PMT and of LaBr3 crystals, and the development of dedicated electronics
Diagnosis and management of Cushing's syndrome: Results of an Italian multicentre study
The past 45 yr' experience with Cushing's syndrome (CS) has led to the awareness of its complex nature and, by the same token, brought about an increase in the diagnostic and therapeutic dilemmas. We carried out a retrospective multicentre study on the diagnostic work-up and treatment in 426 patients with CS, subdivided as follows: 288 with Cushing's disease (CD), 80 with an adrenal adenoma, 24 with an adrenal carcinoma, 25 with ectopic ACTH and/or CRH secretion, and 9 with ACTH-independent nodular adrenal hyperplasia. Normal urinary free cortisol (UFC) values among multiple collections were recorded in about 10% of patients with CS. In 28% of patients with ACTH-independent CS, basal ACTH concentrations were within the normal range but did not respond to CRH stimulation. Measurement of ACTH levels by immunoradiometric assay, rather than by RIA, offered a greater chance of recognizing patients with ACTH-independent CS or ectopic secretion. A 50% increase in ACTH or cortisol levels after CRH yielded a diagnostic accuracy of 86% and 61%, respectively, in the differential diagnosis of ACTH- dependent CS. An 80% decrease in cortisol levels after 8 mg dexamethasone overnight, or in UFC values after the classical 2-day administration, excluded an ectopic secretion but carried a low negative predictive value given the high number of nonsuppressors among patients with CD. Pituitary imaging identified an adenoma in 61% of patients with CD. At inferior petrosal sinus sampling, an ACTH centre: periphery gradient after CRH less than 3, correctly classified all patients with ectopic secretion but misdiagnosed 15% of 76 patients with CD. Transsphenoidal pituitary surgery, the standard therapy for CD, resulted in complete remission (appearance of clinical signs of adrenal insufficiency associated with low/normal UFC excretion and, when available, low/normal morning plasma ACTH and cortisol levels) in 69% of patients. The overall relapse rate after pituitary surgery was 17%. The probability of relapse-free survival, as assessed by Kaplan- Meier analysis, was 95% at 12 months, 84% at 2 yr, and 80% at 3 yr. Risk of relapse was significantly correlated with postoperative baseline plasma ACTH and cortisol peak after CRH. No relapses were observed among patients who did not respond to CRH. Other therapeutic approaches for CD, such as pituitary irradiation and medical therapy, resulted in normalization of cortisol secretion in about half of treated cases. In summary, an accurate selection of the available diagnostic tools leads to the correct diagnosis in the majority of patients with CS. The therapeutic options for CD, adrenal carcinoma, and ectopic secretion are, as yet, not fully satisfactory. The high incidence of relapse after pituitary surgery calls for a prolonged follow-up
T cell defects in patients with ARPC1B germline mutations account for their combined immunodeficiency
ARPC1B is a key factor for the assembly and maintenance of the ARP2/3 complex that is involved in actin branching from an existing filament. Germline bi-allelic mutations in ARPC1B have been recently described in six patients with clinical features of combined immunodeficiency, whose neutrophils and platelets but not T lymphocytes were studied. We hypothesized that ARPC1B-deficiency may also lead to cytoskeleton and functional defects in T cells. We have identified bi-allelic mutations in ARPC1B in six unrelated patients with early-onset disease characterized by severe infections, autoimmune manifestations and thrombocytopenia. Immunological features included T cell lymphopenia, low numbers of na\uefve T cells and hyper-IgE. Alteration in ARPC1B protein structure led to absent/low expression by flow cytometry and confocal microscopy. This molecular defect was associated with the inability of patient-derived T cells to extend an actin-rich lamellipodia upon TCR stimulation and to assemble an immunological synapse. ARPC1B-deficient T cells additionally displayed impaired TCR-mediated proliferation and SDF1-\u3b1-directed migration. Gene transfer of ARPC1B in patient's T cells using a lentiviral vector restored both ARPC1B expression and T-cell proliferation in vitro. In two of the patients, in vivo somatic reversion restored ARPC1B expression in a fraction of lymphocytes and was associated with a skewed TCR repertoire. In one revertant patient, memory CD8+ T cells expressing normal levels of ARPC1B displayed improved T cell migration. Inherited ARPC1B deficiency therefore alters T cell cytoskeletal dynamics and functions, contributing to the clinical features of combined immunodeficiency
Critical barriers to environmental management system implementation in the Nigerian construction industry
This is an accepted manuscript of an article published by Springer in Environmental Management, available online: https://doi.org/10.1007/s00267-021-01473-y
The accepted version of the publication may differ from the final published version.The impact of different hazardous substances of the construction industry being released to the environment is alarming. This constitutes an adverse effect on the quality of life of construction workers and the populace at large. To reduce this menace, Environmental Management System (EMS) was put in place. Meanwhile, the implementation of EMS in the Nigerian construction industry (NCI) is not certain. This study, therefore, investigated the barriers to EMS implementation in the NCI to group them into a smaller form, i.e., fewer numbers. A questionnaire survey was developed and administered to construction professionals in Nigeria using a purposive sampling technique. The retrieved 106 copies of the questionnaires were subjected to both descriptive and inferential statistics such as mean score, standard deviation, analysis of variance test, post hoc test and exploratory factor analysis. An exploratory factor analysis was conducted three times to identify the critical barriers to EMS implementation in the NCI. The study findings reveal three main categories of barriers affecting EMS implementation, namely; (1) knowledge barrier; (2) process barrier; and (3) culture and management barrier. The study concluded that the three factors indicate the major cardinal barriers that could describe the impediment of EMS in the NCI. It was recommended that the training of construction professionals is important to enhance improvement culture in the NCI