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Polyimide is often the first choice to insulate instrumentation and magnet wires working under demanding environmental and operating conditions since it shows good mechanical properties at low temperatures and high radiation resistance. Nevertheless, we have recently discovered that thermoplastic polyimide (TPI) insulated wires may suffer an accelerated brittle failure from a combination of environmental and mechanical stress, summarized as environmental stress cracking (ESC). Amorphous plastics immersed in an aggressive liquid and under a certain stress level, may develop crazes below the stress that would normally cause crazing in air. Certain alkaline hardeners can be considered aggressive toward polyimide. This study reports the causes and effects of environmental stress cracking of thermoplastic polyimide insulated wires subjected to resin systems commonly used in superconducting magnet technologies, and tentatively identifies those that seem more benign. We suspect that ESC can be behind some of the failures (Paschen breakdown under test voltages or even in operation) seen in some superconducting coils.

A Volumetric Neutron Source (VNS) is proposed as a compact tokamak to serve as a qualification testbed for fusion in-vessel components, breeding blanket in particular. The main goal is to determine the minimum size of the machine while maximizing the Neutron Wall Load (NWL). This paper discusses the design parameters and constraints involved in specifying the magnetic cage for VNS. The focus of the study is on sizing the TF (toroidal field) coils and related structures with the plasma magnetic field, as well as assessing how various design constraints influence the machine performance at higher magnetic field strengths. In particular, the trade-off between TF neutron heat load and dose and shielding efficiency. A very preliminary (and still evolving) design point for VNS is presented and discussed.

Purpose: Hypothalamic-pituitary thyrotropic activity (HPta) is crucial since TSH is the mainstay for evaluating primary hypothyroidism (hT) and replacement therapy in clinical practice. Despite TSH values, some patients experience symptoms and metabolic alterations, raising several issues about hT. The aim of the study was to investigate factors influencing the TSH values achieved after a period of hT induced in a standardized and controlled manner (TSH_time1). Methods: Our institutional database was searched to extract records of differentiated thyroid cancer (DTC) patients undergoing a LT4 withdrawal protocol prior to radioiodine (RAI) administration. We collected clinical and biochemical parameters before LT4 discontinuation and after one month of induced hT. We performed Mann-Whitney U-test and linear regression analyses. Results: We included 102 patients, with a median age of 44 years. In univariate analyses, TSH_time1 was correlated with age (p 0.005) and the dose pro Kg/die of LT4 assumed until the discontinuation of LT4 (LT4_dose) (p 0.023). The higher the age, the lower the TSH_time1 level. The higher the LT4_dose, the higher the TSH_time1 level. After multivariate analysis, the fittest model included age, BMI, LT4_dose, and systemic inflammation response index with an adjusted R2of 0.4. Conclusion: The study highlights new mechanisms that influence HPta. HPta progressively reduces with age, and this must be considered when evaluating TSH values in the elderly. Furthermore, we report for the first time a rebound effect of HPta, determined by the dose pro Kg/die of LT4 taken prior to its discontinuation. Inflammation and metabolic status also affect these phenomena.

Purpose: MKNR3is a paternally expressed gene whose mutations are the main cause of central precocious puberty (CPP). Protein circulating levels can be easily measured, as demonstrated in idiopathic CPP and healthy controls. No data are available for patients harboring an MKRN3mutation. Our aim was to perform MKRN3mutation screening and to investigate if circulating protein levels could be a screening tool to identify MKRN3mutation in CPP patients. Methods: We enrolled 140 CPP girls and performed MKRN3mutation analysis. Patients were stratified into two groups: idiopathic CPP (iCPP) and MKRN3 mutation-related CPP (MKRN3-CPP). Clinical characteristics were collected. Serum MKRN3 values were measured by a commercially available ELISA assay kit in MKRN3-CPP and a subgroup of 15 iCPP patients. Results: We identified 5 patients with MKRN3mutations: one was a novel mutation (p.Gln352Arg) while the others were previously reported (p.Arg328Cys, p.Arg345Cys, p.Pro160Cysfs*14, p.Cys410Ter). There was a significant difference in circulating MKRN3 values in MKRN3-CPP compared to iCPP (p< 0.001). In MKRN3-CPP, the subject harboring Pro160Cysfs*14 presented undetectable levels. Subjects carrying the missense mutations p.Arg328Cys and p.Gln352Arg showed divergent circulating protein levels, respectively 40.56 pg/mL and undetectable. The patient with the non-sense mutation reported low but measurable MKRN3 levels (12.72 pg/mL). Conclusions: MKRN3defect in patients with CPP cannot be predicted by MKRN3 circulating levels, although those patients presented lower protein levels than iCPP. Due to the great inter-individual variability of the assay and the lack of reference values, no precise cut-off can be identified to suspect MKRN3 defect.

Background and purpose: Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that enhance the immune response against cancer cells. ICIs are generally well tolerated, although endocrine immune-related adverse events (irAEs) are common. We investigated the risk factors for thyroid irAEs in patients treated with ICIs. Moreover, we evaluated the clinical outcome of subjects who became hypothyroid compared to euthyroid patients. Patients and methods: We retrospectively analyzed a series of 195 consecutively subjects treated with ICIs for metastatic tumors at the University of Naples “Federico II” between January 2014 and March 2020. Only subjects tested for thyroid function before and during the treatment with ICIs were included. Results: In the 96 patients treated with ICIs who were included [66 males, median age: 62 years (27–87)], thyroid irAEs occurred in 36 (37.5%), 16 (16.7%) a transient thyrotoxicosis, and 20 (20.8%) an hypothyroidism (in nine subjects hypothyroidism was preceded by a transient thyrotoxicosis). Only baseline TSH levels above 1.67 mIU/L and positive anti-thyroid antibodies (Ab-T) were associated with a higher risk of hypothyroidism. Patients with hypothyroidism during ICI treatment showed an improved 2-year PFS (HR = 0.82 CI 0.47–1.43; p= 0.0132) and OS (HR = 0.38 CI 95% 0.17–0.80; p= 0.011) compared to euthyroid patients. Conclusions: Baseline TSH levels above 1.67 mIU/L and presence of Ab-T are risk factors for the development of thyroid irAEs. Patients affected by thyroid irAEs showed a longer survival than patients who remained euthyroid.

Metastatic cancer patients generally respond well to treatment with tyrosine kinase inhibitors (TKIs). However, TKI resistance occurs in almost all cases and often leads to a change in treatment. Recent guidelines, including thyroid cancer, raised the possibility of locally treating TKI-resistant oligoprogressive disease, i.e., one or a few progressing lesions in an otherwise treatment-responsive metastatic cancer, thereby obviating the need to change the ongoing TKI. To determine the benefits of this intervention, we reviewed studies on the use of LAT for TKI-treated oligoprogressive cancers. We found that in non-small cell lung cancer at least, LAT prolongs disease control and the duration of exposure to a TKI irrespective of the LAT used. Moreover, we reviewed the local ablative therapies (LATs) that are feasible for the local control of oligoprogressive thyroid cancer. Lastly, we report two illustrative cases of patients with oligoprogressive thyroid cancer treated with two different LATs while on therapy with TKIs. Both LATs extended the duration of disease control and the time of exposure to the ongoing TKI, thereby indicating that LAT is a favorable option for TKI-treated oligoprogressive thyroid cancer. Prospective randomized studies are needed to verify the benefit of LATs in terms of progression-free and overall survival in this increasingly frequent clinical setting.

The natural history of impaired glucose tolerance (IGT) and Type 2 diabetes among obese children is not clear. Although the cut-off for impaired fasting glucose (IFG) has recently been changed from 110 (6.1 mmol/l) to 100 mg/dl (5.6 mmol/l), it does not seem a reliable way to find all subjects with impaired glucose homeostasis. The aim of our study was to determine whether high-normal fasting glucose level could predict the occurrence of IGT and metabolic syndrome. Three hundred and twenty-three Italian obese children and adolescents were included in the study (176 females, mean age 11±2.9 yr; mean body mass index z-score: 3±0.6). Waist circumference, serum glucose, insulin, triglyceride, cholesterol HDL, blood pressure were evaluated and an oral glucose tolerance test (OGTT) was performed. The prevalence of IFG and IGT were respectively 1.5% (5 subjects) and 5% (18 patients); no diabetic patients were found. Metabolic syndrome was diagnosed in 20% of patients. Fasting glycemia values <100 mg/dl (5.6 mmol/l) have been divided in quintiles. Metabolic syndrome prevalence increased across quintiles, although not in a statistically significantly manner, but it could depend on the selected diagnostic criteria as no univocal definition exists for metabolic syndrome in youths. Interestingly high-normal fasting plasma glucose levels constitute an independent risk factor for IGT among obese children and adolescents; therefore, this very easy-to-use parameter may help to identify obese patients at increased risk of diabetes or at least could suggest in which subjects to perform an OGTT.

OBJECTIVE: The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, lovastatin, induces apoptosis in the thyroid cell line TAD-2 and in proliferating normal human thyroid cells in culture, through a p53-independent mechanism involving caspase-3-like proteases. The combination of lovastatin with other anti-neoplastic drugs potentiates chemotherapy of tumors. This drug has been suggested for the chemotherapy of tumors and is potentially useful in the treatment of thyroid proliferative diseases. Based on this premise, we analyzed in more detail the role of some molecular effectors and the role of the caspase family proteases in the lovastatin-induced apoptotic pathway in TAD-2 cells. METHODS: TAD-2 cells were treated with lovastatin to induce apoptosis, and expression of p53, Bc1-2, Bcl-XL and Bax was analyzed by Western blot. Caspase activation was evaluated by the assay of enzymatic activity with chromogenic peptides and Western blot. Nuclear, cytosolic and mitochondrial fractions were prepared by differential centrifugation and the presence of cytochrome c and lamin B was evaluated by Western blot. RESULTS: p53, Bc1-2, Bcl-XL and Bax protein expression were unchanged during apoptosis. Cytochrome c was released from mitochondria into the cytosol, a pivotal event in the activation of caspase-3. Caspase-3 and -6 but not caspase-2 were activated, and proteolysis of PARP and lamin B, a caspase-6 substrate located in the inner nuclear membrane, was demonstrated by Western blot. The nuclear localization of lamin B was also inhibited by lovastatin. CONCLUSIONS: These data demonstrate that, in TAD-2 thyroid cells, lovastatin induces lamin B proteolysis and inhibits its nuclear localization and induces cytochrome c release from mitochondria into the cytosol.

The 144-kDa lambda2 protein of mammalian reovirus catalyzes a number of enzymatic activities in the capping of reovirus mRNA, including the transfer of GMP from GTP to the 5' end of the 5'-diphosphorylated nascent transcript. This reaction proceeds through a covalently autoguanylylated lambda2-GMP intermediate. The smaller size of RNA capping guanylyltransferases from other organisms suggested that the lambda2-associated guanylyltransferase would be only a part of this protein. Limited proteinase K digestion of baculovirus-expressed lambda2 was used to generate an amino-terminal M(r) 42,000 fragment that appears to be both necessary and sufficient for guanylyltransferase activity. Although lysine 226 was identified by previous biochemical studies as the active-site residue that forms a phosphoamide bond with GMP in autoguanylylated lambda2, mutation of lysine 226 to alanine caused only a partial reduction in guanylyltransferase activity at the autoguanylylation step. Alanine substitution for other lysines within the amino-terminal region of lambda2 identified lysine 190 as necessary for autoguanylylation and lysine 171 as an important contributor to autoguanylylation. A novel active-site motif is proposed for the RNA guanylyltransferases of mammalian reoviruses and other Reoviridae members.

BACKGROUND & AIMS: Mutations in the APC gene result in an increased propensity to develop intestinal neoplasia; however, a complete understanding of the mechanisms resulting in tumor formation has remained elusive. Min mice possess a mutation in the APC gene and display a neoplastic phenotype similar to that observed in familial adenomatous polyposis coli in humans. Cyclooxygenase (COX) inhibitors decrease tumor multiplicity in the Min mouse intestine. The present study was designed to determine if there was an increase in COX-2 in adenomas harvested from Min mouse intestine. METHODS: COX-2 messenger RNA levels were determined by Northern blots and reverse-transcription polymerase chain reactions of B6Min x 129 mouse-derived tumors. Protein levels and localization were determined by Western blots and immunohistochemical staining. RESULTS: The Northern blots revealed an approximately threefold increase in the level of COX-2 messenger RNA in Min mouse adenoma compared with normal mucosa. COX-2 protein levels in adenomatous tissues were also approximately threefold higher compared with normal mucosa from the same mouse. Immunohistochemical staining with a monospecific COX-2 antibody confirmed that increases in COX-2 immunoreactivity were restricted to dysplastic and neoplastic foci within intestinal mucosa. CONCLUSIONS: These data show that COX-2 levels may be increased at an early stage in colorectal neoplasia during polyp formation and before invasion. (Gastroenterology 1996 Oct;111(4):1134-40)

The 144-kDa lambda2 protein is a structural component of mammalian reovirus particles and contains the guanylyltransferase activity involved in adding 5' caps to reovirus mRNAs. After incubation of reovirus T3D core particles at 52 degrees C, the lambda2 protein became sensitive to partial protease degradation. Sequential treatments with heat and chymotrypsin caused degradation of a C-terminal portion of lambda2, leaving a 120K core-associated fragment. The four other proteins in cores--lambda1, lambda3, mu2, and sigma2--were not affected by the treatment. Purified cores with cleaved lambda2 were subjected to transmission cryoelectron microscopy and image reconstruction. Reconstruction analysis demonstrated that a distinctive outer region of lambda2 was missing from the modified cores. The degraded region of lambda2 corresponded to the one that contacts the base of the sigma1 protein fiber in reovirus virions and infectious subvirion particles, suggesting that the sigma1-binding region of lambda2 is near its C terminus. Cores with cleaved lambda2 were shown to retain all activities required to transcribe and cap reovirus mRNAs, indicating that the C-terminal region of lambda2 is dispensable for those functions.

One or more proteins in mammalian reovirus core particles mediate two RNA methylation activities, (guanosine-7-N)-methyltransferase and (guanosine-2'-O)-methyltransferase, that contribute to forming the 5' cap 1 structure on viral mRNA. We used UV irradiation to identify core proteins that bind S-adenosyl-L-methionine (SAM), the methyl-group donor for both methyltransferases. A [methyl-3H]SAM-binding site was observed among the reovirus lambda proteins; was shown to be specific by competition with low levels of S-adenosyl-L-homocysteine, the product of methyl-group transfer from SAM; and was subsequently localized to protein lambda2. lambda2 mediates the guanylyltransferase reaction in cap formation and was previously proposed to mediate one or both methylation reactions as well. SAM binding was demonstrated for both lambda2 in cores and lambda2 expressed in insect cells from a recombinant baculovirus. Using three different methods to cleave lambda2, a binding site for SAM was tentatively localized to a central region of lambda2, between residues 792 and 1100, which includes a smaller region with sequence similarity to the SAM-binding pocket of other methyltransferases. Alanine substitutions at positions 827 and 829 within this predicted binding region greatly reduced the capacity of baculovirus-expressed lambda2 protein to undergo UV cross-linking to SAM but had no effects on either the guanylyltransferase activity of this protein or its conformation as judged by partial proteolysis, suggesting that one or both of these residues is essential for SAM binding. Based on these findings, we propose that the two methyltransferase activities involved in mRNA capping by reovirus cores utilize a single SAM-binding pocket within a central region of lambda2.