SARS-CoV-2 mRNA vaccine BNT162b2 triggers a consistent cross-variant humoral and cellular response.

As the SARS-CoV-2 pandemic continues to rage worldwide, the emergence of numerous variants of concern (VOC) represents a challenge for the vaccinal protective efficacy and the reliability of commercially available high-throughput immunoassays. Our study demonstrates the administration of two doses of the BNT162b2 vaccine that elicited a robust SARS-CoV-2-specific immune response which was assessed up to 3 months after full vaccination in a cohort of 37 health care workers (HCWs). SARS-CoV-2-specific antibody response, evaluated by four commercially available chemiluminescence immunoassays (CLIA), was qualitatively consistent with the results provided by the gold-standard in vitro neutralization assay (NTA). However, we could not observe a correlation between the quantity of the antibody detected by CLIA assays and their neutralizing activity tested by NTA. Almost all subjects developed a SARS-CoV-2-specific T-cell response. Moreover, vaccinated HCWs developed a similar protective neutralizing antibodies response against the EU (B.1), Alpha (B.1.1.7), Gamma (P.1), and Eta (B.1.525) SARS-CoV-2 variants, while Beta (B.1.351) and Delta (B.1.617.2) strains displayed a consistent partial immune evasion. These results underline the importance of a solid vaccine-elicited immune response and a robust antibody titre. We believe that these relevant results should be taken into consideration in the definition of future vaccinal strategies.

3D TOF-PET image reconstruction using total variation regularization.

In this paper we introduce a semi-analytic algorithm for 3-dimensional image reconstruction for positron emission tomography (PET). The method consists of the back-projection of the acquired data into the most likely image voxel according to time-of-flight (TOF) information, followed by the filtering step in the image space using an iterative optimization algorithm with a total variation (TV) regularization. TV regularization in image space is more computationally efficient than usual iterative optimization methods for PET reconstruction with full system matrix that use TV regularization. The efficiency comes from the one-time TOF back-projection step that might also be described as a reformatting of the acquired data. An important aspect of our work concerns the evaluation of the filter operator of the linear transform mapping an original radioactive tracer distribution into the TOF back-projected image. We obtain concise, closed-form analytical formula for the filter operator. The proposed method is validated with the Monte Carlo simulations of the NEMA IEC phantom using a one-layer, 50 cm-long cylindrical device called Jagiellonian PET scanner. The results show a better image quality compared with the reference TOF maximum likelihood expectation maximization algorithm.

Performance assessment of the 2 γpositronium imaging with the total-body PET scanners.

PURPOSE: In living organisms, the positron-electron annihilation (occurring during the PET imaging) proceeds in about 30% via creation of a metastable ortho-positronium atom. In the tissue, due to the pick-off and conversion processes, over 98% of ortho-positronia annihilate into two 511 keV photons. In this article, we assess the feasibility for reconstruction of the mean ortho-positronium lifetime image based on annihilations into two photons. The main objectives of this work include the (i) estimation of the sensitivity of the total-body PET scanners for the ortho-positronium mean lifetime imaging using 2γ annihilations and (ii) estimation of the spatial and time resolution of the ortho-positronium image as a function of the coincidence resolving time (CRT) of the scanner. METHODS: Simulations are conducted assuming that radiopharmaceutical is labeled with 44Sc isotope emitting one positron and one prompt gamma. The image is reconstructed on the basis of triple coincidence events. The ortho-positronium lifetime spectrum is determined for each voxel of the image. Calculations were performed for cases of total-body detectors build of (i) LYSO scintillators as used in the EXPLORER PET and (ii) plastic scintillators as anticipated for the cost-effective total-body J-PET scanner. To assess the spatial and time resolution, the four cases were considered assuming that CRT is equal to 500 ps, 140 ps, 50 ps, and 10 ps. RESULTS: The estimated total-body PET sensitivity for the registration and selection of image forming triple coincidences (2γ+γprompt) is larger by a factor of 13.5 (for LYSO PET) and by factor of 5.2 (for plastic PET) with respect to the sensitivity for the standard 2γ imaging by LYSO PET scanners with AFOV = 20 cm. The spatial resolution of the ortho-positronium image is comparable with the resolution achievable when using TOF-FBP algorithms already for CRT = 50 ps. For the 20-min scan, the resolution better than 20 ps is expected for the mean ortho-positronium lifetime image determination. CONCLUSIONS: Ortho-positronium mean lifetime imaging based on the annihilations into two photons and prompt gamma is shown to be feasible with the advent of the high sensitivity total-body PET systems and time resolution of the order of tens of picoseconds.

Estimating relationship between the time over threshold and energy loss by photons in plastic scintillators used in the J-PET scanner.

PURPOSE: The time-over-threshold (TOT) technique is being used widely due to itsimplications in developing the multi-channel readouts, mainly when fast signal processing is required. Using the TOT technique, as a measure of energy loss instead of charge integration methods, significantly reduces the signal readout costs by combining the time and energy information. Therefore, this approach can potentially be utilized in J-PET tomograph which is built from plastic scintillators characterized by fast light signals. The drawback in adopting this technique lies in the non-linear correlation between input energy loss and TOT of the signal. The main motivation behind this work is to develop the relationship between TOT and energy loss and validate it by the J-PET tomograph setup. METHODS: The experiment was performed using a 22Na beta emitter source placed in the center of the J-PET tomograph. This isotope produces photons of two different energies: 511 keV photons from the positron annihilation (direct annihilation or through the formation of a para-positronium atom or pick-off process of ortho-positronium atoms) and a 1275 keV prompt photon. This allows the study of the correlation between TOT values and energy loss for energy ranges up to 1000 keV. Since the photon interacts predominantly via Compton scattering inside the plastic scintillator, there is no direct information of the energy deposition. However, using the J-PET geometry, one can measure the scattering angle of the interacting photon. Since the 22Na source emits photons of two different energies, it is necessary to know unambiguously the energy of incident photons and their corresponding scattering angles in order to estimate energy deposition. In summary, this work presents a dedicated algorithm developed to tag photons of different energies and studying their scattering angles to calculate the energy deposition by the interacting photons. RESULTS: A new method was elaborated to measure the energy loss by photons interacting with plastic scintillators used in the J-PET tomograph. We find the relationship between the energy loss and TOT is non-linear and can be described by the functions TOT = A0 + A1 * ln(E dep + A2) + A3 * (ln(E dep + A2))2 and TOT = A0 - A1 * A2[Formula: see text]. In addition, we also introduced a theoretical model to calculate the TOT as a function of energy loss in plastic scintillators. CONCLUSIONS: A relationship between TOT and energy loss by photons interacting inside the plastic scintillators used in J-PET scanner is established for a deposited energy range of 100-1000 keV.

Flat bands and gaps in twisted double bilayer graphene.

We present electronic structure calculations of twisted double bilayer graphene (TDBG): a tetralayer graphene structure composed of two AB-stacked graphene bilayers with a relative rotation angle between them. Using first-principles calculations, we find that TDBG is semiconducting with a band gap that depends on the twist angle, that can be tuned by an external electric field. The gap is consistent with TDBG symmetry and its magnitude is related to surface effects, driving electron transfer from outer to inner layers. The surface effect competes with an energy upshift of localized states at inner layers, giving rise to the peculiar angle dependence of the band gap, which reduces at low angles. For these low twist angles, the TDBG develops flat bands, in which electrons in the inner layers are localized at the AA regions, as in twisted bilayer graphene.

Efficacy and Safety of Sorafenib After Liver Transplantation: Experience in Our Center.

Recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) is increasing, with a consequent impact on survival. Here we report our experience with sorafenib to treat HCC recurrence after LT. PATIENTS AND METHODS: We undertook a retrospective cohort study of LT patients with recurrent HCC. RESULTS: The study included 12 patients with recurrent HCC after LT between January 2008 and March 2019; 9 were men and 3 women, with a median age of 58 years. Adverse effects were manageable in most patients with symptomatic treatment or with sorafenib dose adjustment. Stable disease was the best response and was achieved. Eight patients (66.7%) died during the study period, 5 (62.5%) due to tumor progression and 3 (37.5%) because of sepsis. The median survival time was 7.5 months.

Chest Wall Implantation Metastasis Caused by Percutaneous Interventional Procedure Appearing 12 Years After Liver Transplantation: A Case Report.

Percutaneous treatments (mainly radiofrequency ablation and ethanol injection) are modes of treatment for hepatocellular carcinoma. Seeding of malignant cells along the percutaneous tract is a very rare complication. We present a case of chest wall metastasis caused by radiofrequency ablation appearing years after liver transplantation.

Atuação dos profissionais da equipe de enfermagem na farmacovigilância: revisão integrativa da literatura / Nursing team professionals"performance in pharmacovigilance: an integrative literature review

Este estudo teve por objetivo caracterizar a prática dos profissionais de enfermagem na farmacovigilância a partir da produção científica nacional e internacional dos últimos 10 anos. Revisão integrativa da literatura realizada no período de agosto a novembro de 2018 nas bases de dados Literatura Latino-Americana e do Caribe em Ciências da Saúde, Base de Dados de Enfermagem, Scientific Electronic Library Online e Medical Literature Analysis and Retrieval System Online, através de descritores preestabelecidos nos Descritores em Ciências da Saúde e cruzados por meio do operador booleano AND. Dos 57 artigos iniciais, 13 compuseram o corpus da pesquisa. Após análise temática e categorização, a atuação dos profissionais de enfermagem contemplou as categorias Atuação assistencial da enfermagem na farmacovigilância e Atuação gerencial e educacional da enfermagem na farmacovigilância. Apesar de limitada e pouco concreta, a atuação da equipe de enfermagem se apresentou na linha de frente da vigilância do consumo de medicamentos.

Medication-overuse headache detoxification reduces headache disability - the Akershus study of chronic headache.

BACKGROUND AND PURPOSE: Medication-overuse headache (MOH) is a chronic headache (≥15 days/month) associated with overuse of acute headache medication. The objective was to investigate headache-related disability before and after self-detoxification from MOH in the general population, as well as possible predictors for successful outcome. METHODS: This was a prospective cohort study. Participants were identified in a cross-sectional epidemiological sample of 30 000 persons aged 30-44 from the general Norwegian population. People with MOH received short information about the possible role of medication overuse in headache chronification. A total of 108 of the 128 participants (84%) were eligible for follow-up 1.5 years later. RESULTS: Using the Migraine Disability Assessment (MIDAS), people with MOH in the general population were heavily disabled (mean MIDAS score 42.1, 95% confidence interval 31.7-52.6) with a majority in the severe disability class. The MIDAS score was significantly reduced at follow-up (P < 0.001) for those with successful self-detoxification. In multivariate analyses, co-occurrence of migraine (P = 0.044) and lower headache frequency at baseline (P = 0.001) increased the odds for successful self-detoxification and reversion to episodic headache. CONCLUSION: Medication-overuse headache causes substantial disability in the general population. Self-detoxification leads to reduced headache frequency and disability, although 24% of the participants did not complete self-detoxification. Detoxification should be offered to MOH patients as early as possible with a focus on headache frequency, disability and psychological distress.

Efficacy and Safety of Anti-TNF-α Agents in Inflammatory Bowel Disease After Liver Transplant: A Case Series.

BACKGROUND: Ulcerative colitis (UC) and Crohn disease (CD) can appear de novo or worsen after liver transplant. Our aim was to assess the efficacy and safety of anti-tumor necrosis-alpha (anti-TNF-α) agents after transplantation. METHODS: We reviewed the clinical database of our center searching for all liver transplant patients with inflammatory bowel disease who were treated with anti-TNF-α agents between 1997 and 2017. Clinical response was assessed from clinical activity indices 12 weeks after starting treatment. The median age of the 6 patients (3 women) was 37 years. Four patients were diagnosed before transplantation (2 UC and 2 CD), and in the other 2 the disease appeared de novo (1 UC and 1 CD). The indications for transplant were primary sclerosing cholangitis (n = 3), cryptogenic cirrhosis (n = 2), and hepatitis C virus cirrhosis (n = 1). RESULTS: Clinical response was seen in 3 of the 6 patients and, in the 3 cases for whom endoscopic data were available, no mucous healing was seen. The only adverse effects noted over a mean follow-up of 15 months were 1 cytomegalovirus infection and 1 severe infusion reaction to infliximab. No patients had recurrence of primary sclerosing cholangitis in the graft, and none of the patients died. CONCLUSION: Use of an anti-TNF-α agent in a liver transplant patient with inflammatory bowel disease may be an effective option, with an acceptable risk-benefit ratio. Further studies are required to confirm their use in this context.

Retransplant Due to Fulminant Hepatic Failure From Hepatitis E Virus: A Case Report.

Hepatitis E virus (HEV) usually causes self-limiting acute liver infections from fecal or oral transmission, though other routes of infection exist (vertical transmission, blood transfusion, zoonosis). It may give rise to fulminant hepatic failure in 1% of cases. Cases have recently been reported of chronic infection evolving to cirrhosis in immunosuppressed patients, such as those with a liver or kidney transplant. Nonetheless, development of acute liver failure in these patients is exceptional, with few cases published. We present a case of acute liver failure due to HEV in a liver transplant patient who required a liver retransplant 9 years after receiving the original transplant.

Chagas disease knocks on our door: a cross-sectional study among Latin American immigrants in Milan, Italy.

OBJECTIVES: We aimed to assess the prevalence and risk factors for Chagas disease (CD) in Latin American immigrants and to evaluate the accuracy of diagnostic tests. Moreover, we offered to all positive subjects a complete free-of-charge clinical/instrumental evaluation as well as benznidazole treatment in order to stage the disease and verify drug tolerability. METHODS: A cross-sectional survey of CD among Latin Americans living in Milan and its metropolitan area was conducted between July 2013 and July 2014. Blood samples were tested for serologic evidence of CD together with a questionnaire covering demographic and clinical-epidemiological information. RESULTS: Forty-eight (9.6%) of the 501 tested subjects were conclusively diagnosed as having CD. The highest prevalence of CD was among those from Bolivia (43/169, 25.4%) and El Salvador (4/68, 5.9%). Older age (adjusted odds ratio (aOR)] 1.05, p =0.004), a Bolivian origin (aOR 8.80; p =0.003), being born in the department of Santa Cruz (aOR 3.72, p =0.047), having lived in mud houses (aOR 2.68; p =0.019), and having an affected relative (aOR 12.77, p =0.001) were independently associated with CD. The ARCHITECT Chagas test showed the highest sensitivity (100%) and specificity (99.8%). Twenty-nine of the subjects with CD (60.4%) underwent disease staging, 10 of whom (35.7%) showed cardiac and/or digestive involvement. Benznidazole treatment was associated with high frequency of adverse reactions (19/27, 70.4%) and permanent discontinuation (8/27, 29.6%). CONCLUSIONS: CD is highly prevalent among Bolivians and Salvadorans living in Milan. Regions with a large Latin American immigrant population should implement programmes of active detection and treatment.

Feasibility studies of the polarization of photons beyond the optical wavelength regime with the J-PET detector.

J-PET is a detector optimized for registration of photons from the electron-positron annihilation via plastic scintillators where photons interact predominantly via Compton scattering. Registration of both primary and scattered photons enables to determinate the linear polarization of the primary photon on the event by event basis with a certain probability. Here we present quantitative results on the feasibility of such polarization measurements of photons from the decay of positronium with the J-PET and explore the physical limitations for the resolution of the polarization determination of 511 keV photons via Compton scattering. For scattering angles of about 82 ∘ (where the best contrast for polarization measurement is theoretically predicted) we find that the single event resolution for the determination of the polarization is about 40 ∘ (predominantly due to properties of the Compton effect). However, for samples larger than ten thousand events the J-PET is capable of determining relative average polarization of these photons with the precision of about few degrees. The obtained results open new perspectives for studies of various physics phenomena such as quantum entanglement and tests of discrete symmetries in decays of positronium and extend the energy range of polarization measurements by five orders of magnitude beyond the optical wavelength regime.

Endoscopic Management of Post-Liver Transplantation Biliary Strictures With the Use of Fully Covered Metallic Stents.

OBJECTIVE: The aim of this work was to evaluate the safety and efficacy of a fully covered self-expandable metal stent (FCSEMS) in the treatment of post-liver transplantation biliary strictures. METHODS: From October 2009 to October 2014, 44 patients with post-liver transplantation biliary stenosis were treated with the use of endoscopic retrograde cholangiography and placement of FCSEMS after informed consent. The FCSEMS was scheduled to remain in situ for 3-6 months. Patients were followed at regular intervals to evaluate for symptoms and liver function tests. Technical success, complications, and patient outcome were analyzed. RESULTS: All of the strictures were anastomotic, 52% having occurred within the 1st year following the transplantation. Placement of the FCSEMS was possible on the 1st attempt in 54% of patients. Stricture resolution at the time of stent removal was seen in 100% of the cases. During an average follow-up of 27.83 ± 18.3 months after stent removal, stenosis recurred in 9 out of 41 patients (21.9%). The average time of recurrence was 11.78 ± 13.3 months. In all of these cases, the recurrence was resolved by means of placement of another FCSEMS. In 4 cases, the recurrence was associated with a migration of the prosthesis, partial in 2 cases and total in 2 cases. Stent migration occurred in a total of 17 of the 41 patients (41.4%), in 13 of the 32 (40.6%) who had no recurrence of stenosis and in 4 of the 9 (44.4%) of those who experienced recurrence. The average numbers of endoscopic retrograde cholangiography studies required per patient were 2.8 in those with no recurrence and 3.3 in those with recurrence. No death was associated with the process. CONCLUSIONS: FCSEMS is a safe effective alternative to plastic stents in the treatment of post-transplantation biliary strictures, resulting in a lower risk of complications and better patient acceptance.