Initial Testing of an Approximated, Fast Calculation Procedure for Personalized Dosimetry in Radionuclide Therapy Based on Planar Whole-Body Scan and Monte-Carlo Specific Dose Rates from the OpenDose Project

Individualized dosimetry in nuclear medicine is currently at least advisable in order to obtain the best risk–benefit balance in terms of the maximal dose to lesions and under-threshold doses to radiosensitive organs. This article aims to propose a procedure for fast dosimetric calculations based on planar whole-body scintigraphy (WBS) images and developed to be employed in everyday clinical practice. Methods: For simplicity and legacy reasons, the method is based on planar imaging dosimetry, complemented with some assumptions on the radiopharmaceutical kinetics empirically derived from single-photon emission tomography/computed tomography (SPECT/CT) image analysis. The idea is to exploit a rough estimate of the time-integrated activity as has been suggested for SPECT/CT dosimetry but using planar images. The resulting further reduction in dose estimation accuracy is moderated by the use of a high-precision Monte-Carlo S-factor, such as those available within the OpenDose project. Results: We moved the problem of individualized dosimetry to a transformed space where comparing doses was imparted to the ICRP Average Male/Female computational phantom, resulting from an activity distribution related to patient’s pharmaceutical uptake. This is a fast method for the personalized dosimetric evaluation of radionuclide therapy, bearing in mind that the resulting doses are meaningful in comparison with thresholds calculated in the same framework. Conclusion: The simplified scheme proposed here can help the community, or even the single physician, establish a quantitative guide-for-the-eye approach to individualized dosimetry

Modulation of Human Immunodeficiency Virus 1 Replication by Interferon Regulatory Factors

Transcription of the human immunodeficiency virus (HIV)-1 is controlled by the cooperation of virally encoded and host regulatory proteins. The Tat protein is essential for viral replication, however, expression of Tat after virus entry requires HIV-1 promoter activation. A sequence in the 5′ HIV-1 LTR, containing a binding site for transcription factors of the interferon regulatory factors (IRF) family has been suggested to be critical for HIV-1 transcription and replication. Here we show that IRF-1 activates HIV-1 LTR transcription in a dose-dependent fashion and in the absence of Tat. This has biological significance since IRF-1 is produced early upon virus entry, both in cell lines and in primary CD4+ T cells, and before expression of Tat. IRF-1 also cooperates with Tat in amplifying virus gene transcription and replication. This cooperation depends upon a physical interaction that is blocked by overexpression of IRF-8, the natural repressor of IRF-1, and, in turn is released by overexpression of IRF-1. These data suggest a key role of IRF-1 in the early phase of viral replication and/or during viral reactivation from latency, when viral transactivators are absent or present at very low levels, and suggest that the interplay between IRF-1 and IRF-8 may play a key role in virus latency

Exploratory findings from a prematurely closed international, multicentre, academic trial: RAVELLO, a phase III study of regorafenib versus placebo as maintenance therapy after first-line treatment in RAS wild-type metastatic colorectal cancer

Background In patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC), the role of maintenance therapy after first-line treatment with chemotherapy plus antiepidermal growth factor receptor (EGFR) monoclonal antibodies (MoAb) is still an object of debate. Methods We assessed the efficacy and safety of regorafenib as a switch maintenance strategy after upfront 5-fluorouracil-based chemotherapy plus an anti- EGFR MoAb in patients with RAS WT mCRC. RAVELLO was a phase III, international, double-blind, placebocontrolled, academic trial. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival and toxicity. Regorafenib or placebo were administered daily for 3 weeks of 4-week cycle until disease progression or unacceptable toxicity, up to 24 months. Results The study was stopped prematurely due to slow accrual and lack of funding after the randomisation of 21 patients: 11 in the regorafenib arm and 10 in the placebo arm. The small sample size precludes any statistical analysis. Toxicity was acceptable and consistent with the known regorafenib safety profile. Median PFS was similar in the two arms. However, a subgroup of patients treated with regorafenib experienced a remarkably long PFS. Three patients were progression free at 9 months in the regorafenib arm versus one patient in the placebo arm, whereas at 12 months two regorafenib-treated patients were still progression free versus none in the placebo arm. Conclusion RAVELLO trial demonstrated that growing financial and bureaucratic hurdles affect the feasibility of independent academic research. Although stopped prematurely and within the limited sample size, RAVELLO suggests that regorafenib has not a major activity in maintenance setting after upfront chemotherapy and anti-EGFR MoAb. However, a subgroup of patients experienced a remarkable long PFS, indicating that a better refinement of the patient population would help to identify subjects that might benefit from a regorafenib personalised approach in the switch maintenance settin

HIV-1 tat addresses dendritic cells to induce a predominant th1-type adaptive immune response that appears prevalent in the asymptomatic stage of infection

Tat is an early regulatory protein that plays a major role in human HIV-1 replication and AIDS pathogenesis, and therefore, it represents a key target for the host immune response. In natural infection, however, Abs against Tat are produced only by a small fraction (∼20%) of asymptomatic individuals and are rarely seen in progressors, suggesting that Tat may possess properties diverting the adaptive immunity from generating humoral responses. Here we show that a Th1-type T cell response against Tat is predominant over a Th2-type B cell response in natural HIV-1 infection. This is likely due to the capability of Tat to selectively target and very efficiently enter CD1a-expressing monocyte-derived dendritic cells (MDDC), which represent a primary target for the recognition and response to virus Ag. Upon cellular uptake, Tat induces MDDC maturation and Th1-associated cytokines and β-chemokines production and polarizes the immune response in vitro to the Th1 pattern through the transcriptional activation of TNF-αgene expression. This requires the full conservation of Tat transactivation activity since neither MDDC maturation nor TNF-α production are found with either an oxidized Tat, which does not enter MDDC, or with a Tat protein mutated in the cysteine-rich region (cys22 Tat), which enters MDDC as the wild-type Tat but is transactivation silent. Consistently with these data, inoculation of monkeys with the native wild-type Tat induced a predominant Th1 response, whereas cys22 Tat generated mostly Th2 responses, therefore providing evidence that Tat induces a predominant Th1 polarized adaptive immune response in the host. Copyright © 2009 by The American Association of Immunologists, Inc

Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign

Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p < .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p < .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come

Role of prenatal magnetic resonance imaging in fetuses with isolated mild or moderate ventriculomegaly in the era of neurosonography: international multicenter study

Objectives To assess the role of fetal magnetic resonance imaging (MRI) in detecting associated anomalies in fetuses presenting with mild or moderate isolated ventriculomegaly (VM) undergoing multiplanar ultrasound evaluation of the fetal brain. Methods This was a multicenter, retrospective, cohort study involving 15 referral fetal medicine centers in Italy, the UK and Spain. Inclusion criteria were fetuses affected by isolated mild (ventricular atrial diameter, 10.0–11.9 mm) or moderate (ventricular atrial diameter, 12.0–14.9 mm) VM on ultrasound, defined as VM with normal karyotype and no other additional central nervous system (CNS) or extra‐CNS anomalies on ultrasound, undergoing detailed assessment of the fetal brain using a multiplanar approach as suggested by the International Society of Ultrasound in Obstetrics and Gynecology guidelines for the fetal neurosonogram, followed by fetal MRI. The primary outcome of the study was to report the incidence of additional CNS anomalies detected exclusively on prenatal MRI and missed on ultrasound, while the secondary aim was to estimate the incidence of additional anomalies detected exclusively after birth and missed on prenatal imaging (ultrasound and MRI). Subgroup analysis according to gestational age at MRI (< 24 vs ≥ 24 weeks), laterality of VM (unilateral vs bilateral) and severity of dilatation (mild vs moderate VM) were also performed. Results Five hundred and fifty‐six fetuses with a prenatal diagnosis of isolated mild or moderate VM on ultrasound were included in the analysis. Additional structural anomalies were detected on prenatal MRI and missed on ultrasound in 5.4% (95% CI, 3.8–7.6%) of cases. When considering the type of anomaly, supratentorial intracranial hemorrhage was detected on MRI in 26.7% of fetuses, while polymicrogyria and lissencephaly were detected in 20.0% and 13.3% of cases, respectively. Hypoplasia of the corpus callosum was detected on MRI in 6.7% of cases, while dysgenesis was detected in 3.3%. Fetuses with an associated anomaly detected only on MRI were more likely to have moderate than mild VM (60.0% vs 17.7%; P < 0.001), while there was no significant difference in the proportion of cases with bilateral VM between the two groups (P = 0.2). Logistic regression analysis showed that lower maternal body mass index (adjusted odds ratio (aOR), 0.85 (95% CI, 0.7–0.99); P = 0.030), the presence of moderate VM (aOR, 5.8 (95% CI, 2.6–13.4); P < 0.001) and gestational age at MRI ≥ 24 weeks (aOR, 4.1 (95% CI, 1.1–15.3); P = 0.038) were associated independently with the probability of detecting an associated anomaly on MRI. Associated anomalies were detected exclusively at birth and missed on prenatal imaging in 3.8% of cases. Conclusions The incidence of an associated fetal anomaly missed on ultrasound and detected only on fetal MRI in fetuses with isolated mild or moderate VM undergoing neurosonography is lower than that reported previously. The large majority of these anomalies are difficult to detect on ultrasound. The findings from this study support the practice of MRI assessment in every fetus with a prenatal diagnosis of VM, although parents can be reassured of the low risk of an associated anomaly when VM is isolated on neurosonography

Functional and morphological investigation on Lactobacillus plantarum subs plantarum grown in the presence of prebiotics.

Since many decades, food and health companies showed an increasing interest in using probiotics ad dietary adjusts. To produce the desired benefits, probiotics should persist in the product as viable cells during its shelf life. Probiotics are food components capable to resist host digestion and absorption, and are fermented by microbiota, which can stimulate the growth and/or activity of specific positive bacteria, generating also the production of specific useful short chain fatty acids. The growth and viability of a probiotic strain of Lactobacillus plantarum subs. plantarum during a simulated gastrointestinal transit were evaluated, when strains were grown using inulin or pectin as carbon source, compared to glucose used as control. The in vitro coaggregation of the strain with E.coli as well as the potential morphological changes (by SEM) were also investigated. Pectin and inulin, in contrast induced a greeter cell stress resistance against gastrointestinal juices (Delta log 10=1.5 and 2.4 colony forming units/ml. respectively) conversely to glucose /delta log 10=4.0). The presence of the two prebiotics positively affected the capability of the strain to co-aggregate E.coli: inulin and pectin at the same way increased such property, with an increase of about 20% respect to the initial value of co-aggregation observed using glucose as energy source. SEM analysis did non show any morphological difference