Moloney murine leukemia virus decay mediated by retroviral reverse transcriptase degradation of genomic RNA

AbstractRetroviral vectors are powerful tools for the introduction of transgenes into mammalian cells and for long-term gene expression. However, their application is often limited by a rapid loss of bioactivity: retroviruses spontaneously loose activity at 37 °C, with a half-life of 4 to 9 h depending on the retrovirus type. We sought to determine which components of the retrovirus are responsible for this loss in bioactivity and to obtain a quantitative characterization of their stability. To this end, we focused on RNA and viral proteins, two major components that we hypothesized may undergo degradation and negatively influence viral infectivity. Reverse transcription PCR (RT-PCR) targeting RNA encoding portions of the viral genome clearly demonstrated time-dependent degradation of RNA which correlated with the loss in viral bioactivity. Circular dichroism spectroscopy, SDS-PAGE and two-dimensional SDS-PAGE analyses of viral proteins did not show any change in secondary structure or evidence of proteolysis. The mechanism underlying the degradation of viral RNA was investigated by site-directed mutagenesis of proteins encoded by the viral genome. Reverse transcriptase and protease mutants exhibited enhanced RNA stability in comparison to wild type recombinant virus, suggesting that the degradation of RNA, and the corresponding virus loss of activity, is mediated by the reverse transcriptase enzyme

The role of imaging in the diagnosis of recurrence of primary seminal vesicle adenocarcinoma

Primary seminal vesicle (SV) adenocarcinoma is a rare tumor. A small amount of data about the role of imaging to detect tumor recurrence is available. We report the case of a 58-year-old patient with primary SV clear-cell well-differentiated adenocarcinoma. Clinical and instrumental examinations were negative for the 32 months after treatments when computed tomography scan, [(18)F]fluoro-D-glucose positron emission tomography/computed tomography and pelvic magnetic resonance imaging showed the appearance of a lesion in the left perineal muscle suspected for recurrence. Patient was symptomless. Cytology of the suspected lesion confirmed SV adenocarcinoma recurrence. The combined approach, using radiological and nuclear medicine techniques, seems to be effective in the follow-up of SV adenocarcinoma. Technological advances, together with awareness of this rare tumor, have the potential of improving patients outcomes not only by providing earlier detection and accurate staging, but also by detecting recurrence and thereby avoiding delays and therapeutic dilemmas

Long-term survival in elderly patients with a do-not-intubate order treated with noninvasive mechanical ventilation

Paolo Scarpazza1, Cristoforo Incorvaia2, Paolo Amboni3, Giuseppe di Franco1, Stefania Raschi1, Pierfranco Usai1, Monica Bernareggi1, Cristiano Bonacina1, Chiara Melacini1, Roberta Cattaneo1, Serena Bencini1, Chiara Pravettoni2, Gian Galeazzo Riario-Sforza2, Gianni Passalacqua4, Walter Casali11Divisione di Broncopneumotisiologia, Ospedale Civile, Vimercate, Italy; 2Pulmonary Rehabilitation, Istituti Clinici di Perfezionamento, Milan, Italy; 3Clinical Chemistry Laboratory, Ospedali Riuniti, Bergamo, Italy; 4Allergy and Respiratory Diseases, University Of Genoa, Genoa, ItalyBackground: Noninvasive mechanical ventilation (NIMV) is an effective tool in treating patients with acute respiratory failure (ARF), since it reduces both the need for endotracheal intubation and the mortality in comparison with nonventilated patients. A particular issue is represented by the outcome of NIMV in patients referred to the emergency department for ARF and with a do-not-intubate (DNI) status because of advanced age or excessively critical conditions. This study evaluated long-term survival in a group of elderly patients with acute hypercapnic ARF who had a DNI order and who were successfully treated by NIMV.Methods: The population consisted of 54 patients with a favorable outcome after NIMV for ARF. They were followed up for 3 years by regular control visits, with at least one visit every 4 months, or as needed according to the patient’s condition. Of these, 31 continued NIMV at home and 23 were on long-term oxygen therapy (LTOT) alone.Results: A total of 16 of the 52 patients had not survived at the 1-year follow-up, and another eight patients died during the 3-year observation, with an overall mortality rate of 30.8% after 1 year and 46.2% after 3 years. Comparing patients who continued NIMV at home with those who were on LTOT alone, 9 of the 29 patients on home NIMV died (6 after 1 year and 3 after 3 years) and 15 of the 23 patients on LTOT alone died (10 after 1 year and 5 after 3 years).Conclusion: These results show that elderly patients with ARF successfully treated by NIMV following a DNI order have a satisfactory long-term survival.Keywords: COPD, acute respiratory failure, mortality rate, respiratory failur

Chronic Treatment with Ivabradine Does Not Affect Cardiovascular Autonomic Control in Rats

A low resting heart rate (HR) would be of great benefit in cardiovascular diseases. Ivabradine a novel selective inhibitor of hyperpolarization-activated cyclic nucleotide gated (HCN) channels- has emerged as a promising HR lowering drug. Its effects on the autonomic HR control are little known. This study assessed the effects of chronic treatment with ivabradine on the modulatory, reflex and tonic cardiovascular autonomic control and on the renal sympathetic nerve activity (RSNA). Male Wistar rats were divided in 2 groups, receiving intraperitoneal injections of vehicle (VEH) or ivabradine (IVA) during 7 or 8 consecutive days. Rats were submitted to vessels cannulation to perform arterial blood pressure (AP) and HR recordings in freely moving rats. Time series of resting pulse interval and systolic AP were used to measure cardiovascular variability parameters. We also assessed the baroreflex, chemoreflex and the Bezold-Jarish reflex sensitivities. To better evaluate the effects of ivabradine on the autonomic control of the heart, we performed sympathetic and vagal autonomic blockade. As expected, ivabradine treated rats showed a lower resting (VEH: 362 +/- 16 bpm vs. IVA: 260 +/- 14 bpm, p = 0.0005) and intrinsic HR (VEH: 369 +/- 9 bpm vs. IVA: 326 +/- 11 bpm, p = 0.0146). However, the chronic treatment with ivabradine did not change normalized HR spectral parameters LF (nu) (VEH: 24.2 +/- 4.6 vs. IVA: 29.8 +/- 6.4p > 0.05)HF (nu) (VEH: 75.1 +/- 3.7 vs. IVA: 69.2 +/- 5.8p > 0.05), any cardiovascular reflexes, neither the tonic autonomic control of the HR (tonic sympathovagal indexVEH: 0.91 +/- 0.02 vs. IVA: 0.88 +/- 0.03, p = 0.3494). We performed the AP, HR and RSNA recordings in urethane-anesthetized rats. The chronic treatment with ivabradine reduced the resting HR (VEH: 364 +/- 12 bpm vs. IVA: 207 +/- 11 bpm, p < 0.0001), without affecting RSNA (VEH: 117 +/- 16 vs. IVA: 120 +/- 9 spikes/s, p = 0.9100) and mean arterial pressure (VEH: 70 +/- 4 vs. IVA: 77 +/- 6 mmHg, p = 0.3293). Our results suggest that, in health rats, the long-term treatment with ivabradine directly reduces the HR without changing the RSNA modulation and the reflex and tonic autonomic control of the heart.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Fundacao de Amparo a Pesquisa de Minas Gerais (FAPEMIG)Universidade Federal de Ouro Preto (UFOP)Universidade Federal do Triangulo Mineiro (UFTM), BrazilUniv Fed Ouro Preto, Inst Exact & Biol Sci, Dept Biol Sci, Lab Cardiovasc Physiol, Ouro Preto, BrazilUniv Fed Ouro Preto, CBIOL NUPEB, Grad Program Biol Sci, Ouro Preto, BrazilUniv Fed Minas Gerais, Inst Biol Sci, Dept Physiol & Biophys, Lab Hypertens, Belo Horizonte, MG, BrazilUniv Fed Sao Paulo, Inst Sci & Technol, Biomed Engn Lab, Sao Jose Dos Campos, BrazilUniv Uberaba, Dept Physiol, Uberaba, BrazilUniv Milan, Osped Maggiore Policlin, IRCCS Ca Granda Fdn, Dept Clin Sci & Community Hlth, Milan, ItalyFed Univ Trianaulo Pvlineiro, Inst Biol & Nat Sci, Dept Physiol, Uberaba, BrazilUniv Fed Sao Paulo, Inst Sci & Technol, Biomed Engn Lab, Sao Jose Dos Campos, BrazilCNPq: 400851/2014-8Web of Scienc

Determination of stellar parameters for Ariel targets: a comparison analysis between different spectroscopic methods

Ariel has been selected as the next ESA M4 science mission and it is expected to be launched in 2028. During its 4-year mission, Ariel will observe the atmospheres of a large and diversified population of transiting exoplanets. A key factor for the achievement of the scientific goal of Ariel is the selection strategy for the definition of the input target list. A meaningful choice of the targets requires an accurate knowledge of the planet hosting star properties and this is necessary to be obtained well before the launch. In this work, we present the results of a bench-marking analysis between three different spectroscopic techniques used to determine stellar parameters for a selected number of targets belonging to the Ariel reference sample. We aim to consolidate a method that will be used to homogeneously determine the stellar parameters of the complete Ariel reference sample. Homogeneous, accurate and precise derivation of stellar parameters is crucial for characterising exoplanet-host stars and in turn is a key factor for the accuracy of the planet properties

Three cases of bone metastases in patients with gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are rare, but represent the most common mesenchymal neoplasms of the gastrointestinal tract. Tumor resection is the treatment of choice for localized disease. Tyrosine kinase inhibitors (imatinib, sunitinib) are the standard therapy for metastatic or unresectable GISTs. GISTs usually metastasize to the liver and peritoneum. Bone metastases are uncommon. We describe three cases of bone metastases in patients with advanced GISTs: two women (82 and 54 years of age), and one man (62 years of age). Bones metastases involved the spine, pelvis and ribs in one patient, multiple vertebral bodies and pelvis in one, and the spine and iliac wings in the third case. The lesions presented a lytic pattern in all cases. Two patients presented with multiple bone metastases at the time of initial diagnosis and one patient after seven years during the follow-up period. This report describes the diagnosis and treatment of the lesions and may help clinicians to manage bones metastases in GIST patients

Ariel stellar characterisation. I. Homogeneous stellar parameters of 187 FGK planet host stars: Description and validation of the method

Context. In 2020 the European Space Agency selected Ariel as the next mission to join the space fleet of observatories to study planets outside our Solar System. Ariel will be devoted to the characterisation of 1000 planetary atmospheres in order to understand what exoplanets are made of, how they form, and how they evolve. To achieve the last two goals all planets need to be studied within the context of their own host stars, which in turn must be analysed with the same technique, in a uniform way. Aims: We present the spectro-photometric method we developed to infer the atmospheric parameters of the known host stars in the Tier 1 of the Ariel Reference Sample. Methods: Our method is based on an iterative approach that combines spectral analysis, the determination of the surface gravity from Gaia data, and the determination of stellar masses from isochrone fitting. We validated our approach with the analysis of a control sample, composed of members of three open clusters with well-known ages and metallicities. Results: We measured effective temperature Teff, surface gravity log g, and the metallicity [Fe/H] of 187 F-G-K stars within the Ariel Reference Sample. We presented the general properties of the sample, including their kinematics, which allows us to classify them into thin- and thick-disc populations. Conclusions: A homogeneous determination of the parameters of the host stars is fundamental in the study of the stars themselves and their planetary systems. Our analysis systematically improves agreement with theoretical models and decreases uncertainties in the mass estimate (from 0.21 ± 0.30 to 0.10 ± 0.02 M⊙), providing useful data for the Ariel consortium and the astronomical community at large. Tables A.1 and A.2 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/663/A161</A

Preclinical evaluation of KIT/PDGFRA and mTOR inhibitors in gastrointestinal stromal tumors using small animal FDG PET

<p>Abstract</p> <p>Background</p> <p>Primary and secondary drug resistance to imatinib and sunitinib in patients with gastrointestinal stromal tumors (GISTs) has led to a pressing need for new therapeutic strategies such as drug combinations. Most GISTs are caused by mutations in the KIT receptor, leading to upregulated KIT tyrosine kinase activity. Imatinib and nilotinib directly inhibit the kinase activity of KIT, while RAD001 (everolimus) inhibits mTOR. We report a preclinical study on drug combinations in a xenograft model of GIST in which effects on tumor dimensions and metabolic activity were assessed by small animal PET imaging.</p> <p>Methods</p> <p>Rag2-/-; γcommon -/- male mice were injected s.c. into the right leg with GIST 882. The animals were randomized into 6 groups of 6 animals each for different treatment regimens: No therapy (control), imatinib (150 mg/kg b.i.d.) by oral gavage for 6 days, then once/day for another 7 days, everolimus (10 mg/kg/d.) by oral gavage, everolimus (10 mg/kg/d.) + imatinib (150 mg/kg b.i.d.) by oral gavage for 6 days, then once/day for another 7 days, nilotinib (75 mg/kg/d.) by oral gavage, nilotinib (75 mg/kg/d.) + imatinib (150 mg/kg b.i.d) by oral gavage for 6 days, then once/day for another 7 days. Tumor growth control was evaluated by measuring tumor volume (cm³). Small animal PET (GE Explore tomography) was used to evaluate tumor metabolism and performed in one animal per group at base-line then after 4 and 13 days of treatment.</p> <p>Results</p> <p>After a median latency time of 31 days, tumors grew in all animals (volume 0,06-0,15 cm³) and the treatments began at day 38 after cell injection. Tumor volume control (cm3) after 13 days of treatment was > 0.5 for imatinib alone and nilotinib alone, and < 0.5 for the 2 combinations of drugs and for everolimus alone. The baseline FDG uptake was positive in all animals. FDG/SUV/TBR was strongly reduced over time by everolimus both as a single agent and in combination with imatinib respectively: 3.1 vs. 2.3 vs. 1.9 and 2.5 vs 2.3 vs 0.</p> <p>Conclusions</p> <p>As single agents, all drugs showed an anti-tumor effect in GIST xenografts but everolimus was superior. The everolimus plus imatinib combination appeared to be the most active regimen both in terms of inhibiting tumor growth and tumor metabolism. The integration of everolimus in GIST treatment merits further investigation.</p