University of Siena

About: University of Siena is a education organization based out in Siena, Italy. It is known for research contribution in the topics: Population & Cancer. The organization has 12179 authors who have published 33334 publications receiving 1008287 citations. The organization is also known as: Università degli studi di Siena & Universita degli studi di Siena.

Iodine Biokinetics and Dosimetry in Radioiodine Therapy of Thyroid Cancer: Procedures and Results of a Prospective International Controlled Study of Ablation After rhTSH or Hormone Withdrawal

Abstract: study of the effectiveness of ablation therapy with 3.7 GBq 131 I in differentiated thyroid cancer after stimulation with recombinant human TSH (rhTSH) or by thyroid hormone withdrawal (THW) are presented. Methods: Sixty-three patients were randomized after thyroidectomy to either the THW or the rhTSH group. Scintigraphic neck images were acquired starting 48 h after radioiodine administration to assess biokinetics in the thyroid remnant. The activity in blood samples was quantified and data from whole-body probe measurements and scintigraphic whole-body scans were combined to deduce retention curves in blood and whole body, respectively. The absorbed dose to the blood was calculated using a modified approach based on the formalism of the MIRD Committee of the Society of Nuclear Medicine. Results: The effective half-time in the remnant thyroid tissuewassignificantlylongerafterrhTSHthanTHW(67.6 648.8 vs. 48.0 6 52.6 h, respectively; P 5 0.01), whereas the observed differencesofthemean48-h 131 Iuptakes(0.5% 60.7%vs.0.9% 6 1.0% after THW; P 5 0.1) and residence times (0.9 6 1.3 vs. 1.4 6 1.5 h after THW; P 5 0.1) between the rhTSH and THW groups were not statistically significant. The specific absorbed dose to the blood was significantly (P ,0.0001) lower after administration of rhTSH (mean, 0.109 6 0.028 mGy/MBq; maximum, 0.18 mGy/MBq) than after THW (mean, 0.167 6 0.061 mGy/MBq; maximum, 0.35 mGy/MBq), indicating that higher activities of radioiodine might be safely administered after exogenousstimulation withrhTSH.Conclusion:Indication ofaninfluence of the residence time of radioiodine in the blood on the fractional uptake into thyroid remnant was found. A novel regimen is proposed in which therapeutic activities to be administered are determined from the individual specific blood dose.

Effect of cigarette smoking on periodontal healing following GTR in infrabony defects. A preliminary retrospective study.

Abstract: This retrospective study examined the effect of cigarette smoking on the healing response following guided tissue regeneration (GTR) in deep infrabony defects. 71 defects in 51 patients underwent GTR with teflon membranes. 20 patients (32 defects) smoked more than 10 cigarettes per day, while 31 patients (39 defects) did not smoke. Clinical measurements were available at baseline, at membrane removal and at the 1-year follow-up. The oral hygiene of both groups was good, but smokers had significantly higher full-mouth plaque scores. No significant differences were observed between smokers and non-smokers in terms of % of tissue gained at membrane removal. At the 1-year follow-up, however, smokers gained significantly less probing attachment level than non-smokers (2.1 +/- 1.2 mm compared with 5.2 +/- 1.9 mm). A multivariate model, correcting for the oral hygiene level of the patients and the depth of the infrabony component, indicated that smoking was in itself a significant factor in determining the clinical outcome. A risk-assessment analysis indicated that smokers had a significantly greater risk than non-smokers to display a reduced probing attachment level gain following GTR. It is concluded that cigarette smoking is associated with a reduced healing response after GTR treatment, and may be responsible, at least in part, for the observed results.

Disease-Modifying Therapies and Coronavirus Disease 2019 Severity in Multiple Sclerosis.

Abstract: OBJECTIVE: This study was undertaken to assess the impact of immunosuppressive and immunomodulatory therapies on the severity of coronavirus disease 2019 (COVID-19) in people with multiple sclerosis (PwMS). METHODS: We retrospectively collected data of PwMS with suspected or confirmed COVID-19. All the patients had complete follow-up to death or recovery. Severe COVID-19 was defined by a 3-level variable: mild disease not requiring hospitalization versus pneumonia or hospitalization versus intensive care unit (ICU) admission or death. We evaluated baseline characteristics and MS therapies associated with severe COVID-19 by multivariate and propensity score (PS)-weighted ordinal logistic models. Sensitivity analyses were run to confirm the results. RESULTS: Of 844 PwMS with suspected (n = 565) or confirmed (n = 279) COVID-19, 13 (1.54%) died; 11 of them were in a progressive MS phase, and 8 were without any therapy. Thirty-eight (4.5%) were admitted to an ICU; 99 (11.7%) had radiologically documented pneumonia; 96 (11.4%) were hospitalized. After adjusting for region, age, sex, progressive MS course, Expanded Disability Status Scale, disease duration, body mass index, comorbidities, and recent methylprednisolone use, therapy with an anti-CD20 agent (ocrelizumab or rituximab) was significantly associated (odds ratio [OR] = 2.37, 95% confidence interval [CI] = 1.18-4.74, p = 0.015) with increased risk of severe COVID-19. Recent use (<1 month) of methylprednisolone was also associated with a worse outcome (OR = 5.24, 95% CI = 2.20-12.53, p = 0.001). Results were confirmed by the PS-weighted analysis and by all the sensitivity analyses. INTERPRETATION: This study showed an acceptable level of safety of therapies with a broad array of mechanisms of action. However, some specific elements of risk emerged. These will need to be considered while the COVID-19 pandemic persists. ANN NEUROL 2021;89:780-789.

GW150914: implications for the stochastic gravitational wave background from binary black holes

Abstract: The LIGO detection of the gravitational wave transient GW150914, from the inspiral and merger of two black holes with masses $\gtrsim 30\, \text{M}_\odot$, suggests a population of binary black holes with relatively high mass. This observation implies that the stochastic gravitational-wave background from binary black holes, created from the incoherent superposition of all the merging binaries in the Universe, could be higher than previously expected. Using the properties of GW150914, we estimate the energy density of such a background from binary black holes. In the most sensitive part of the Advanced LIGO/Virgo band for stochastic backgrounds (near 25 Hz), we predict $\Omega_\text{GW}(f=25 Hz) = 1.1_{-0.9}^{+2.7} \times 10^{-9}$ with 90\% confidence. This prediction is robustly demonstrated for a variety of formation scenarios with different parameters. The differences between models are small compared to the statistical uncertainty arising from the currently poorly constrained local coalescence rate. We conclude that this background is potentially measurable by the Advanced LIGO/Virgo detectors operating at their projected final sensitivity.