On the photon Green functions in curved space-time

Quantization of electrodynamics in curved space-time in the Lorenz gauge and with arbitrary gauge parameter makes it necessary to study Green functions of non-minimal operators with variable coefficients. Starting from the integral representation of photon Green functions, we link them to the evaluation of integrals involving Gamma functions. Eventually, the full asymptotic expansion of the Feynman photon Green function at small values of the world function, as well as its explicit dependence on the gauge parameter, are obtained without adding by hand a mass term to the Faddeev--Popov Lagrangian. Coincidence limits of second covariant derivatives of the associated Hadamard function are also evaluated, as a first step towards the energy-momentum tensor in the non-minimal case.Comment: 22 pages, plain Tex. All sections and appendices have been improve

Towards weighing the condensation energy to ascertain the Archimedes force of vacuum

The force exerted by the gravitational field on a Casimir cavity in terms of Archimedes force of vacuum is discussed, the force that can be tested against observation is identified, and it is shown that the present technology makes it possible to perform the first experimental tests. The use of suitable high-Tc superconductors as modulators of Archimedes force is motivated. The possibility is analyzed of using gravitational wave interferometers as detectors of the force, transported through an optical spring from the Archimedes vacuum force apparatus to the gravitational interferometer test masses to maintain the two systems well separated. The use of balances to actuate and detect the force is also analyzed, the different solutions are compared, and the most important experimental issues are discussed.Comment: Revtex, 33 pages, 8 figures. In the final version, the title has been changed, and all sections have been improved, while 2 appendices have been adde

Mitogen-activated kinase kinase kinase 1 inhibits hedgehog signaling and medulloblastoma growth through GLI1 phosphorylation

The aberrant activation of hedgehog (HH) signaling is a leading cause of the development of medulloblastoma, a pediatric tumor of the cerebellum. The FDA‑approved HH inhibitor, Vismodegib, which targets the transmembrane transducer SMO, has shown limited efficacy in patients with medulloblastoma, due to compensatory mechanisms that maintain an active HH‑GLI signaling status. Thus, the identification of novel actionable mechanisms, directly affecting the activity of the HH‑regulated GLI transcription factors is an important goal for these malignancies. In this study, using gene expression and reporter assays, combined with biochemical and cellular analyses, we demonstrate that mitogen‑activated kinase kinase kinase 1 (MEKK1), the most upstream kinase of the mitogen‑activated protein kinase (MAPK) phosphorylation modules, suppresses HH signaling by associating and phosphorylating GLI1, the most potent HH‑regulated transcription factor. Phosphorylation occurred at multiple residues in the C‑terminal region of GLI1 and was followed by an increased association with the cytoplasmic proteins 14‑3‑3. Of note, the enforced expression of MEKK1 or the exposure of medulloblastoma cells to the MEKK1 activator, Nocodazole, resulted in a marked inhibitory effect on GLI1 activity and tumor cell proliferation and viability. Taken together, the results of this study shed light on a novel regulatory mechanism of HH signaling, with potentially relevant implications in cancer therapy

Type III pleuropulmonary blastoma in a 7-month-old female baby with impending respiratory failure: a case report

INTRODUCTION: Pleuropulmonary blastoma is a very rare, aggressive, embryonal pulmonary neoplasm which mostly affects children under the age of 5. According to the histopathological features, three subtypes of pleuropulmonary blastoma have been recognized: type I (purely cystic), type II (grossly visible cystic and solid elements) and type III (purely solid). Characteristics of type I and type II blastoma allow an earlier diagnosis compared with type III. Here we present a case report of an unusual presentation of type III pleuropulmonary blastoma. CASE PRESENTATION: We describe the case of a 7-month-old female baby of Italian mother and Kurdish father who was diagnosed with type III pleuropulmonary blastoma, which entirely occupied her right hemithorax. CONCLUSIONS: The reported case is an unusual presentation because type III pleuropulmonary blastoma typically occurs in older children. The complete re-expansion of her residual, previously totally compressed, right lung observed immediately after the resection of the lesion suggests an atypical rapid growth of this embryonal tumor in the late phase of gestation or after delivery. This case report suggests that, in addition to other childhood tumors, type III pleuropulmonary blastoma should be included in the differential diagnosis of solid nonhomogeneous thoracic large masses, compressing the mediastinal and chest wall structures in infants. This is an original case report of interest for several specialities such us pediatrics, radiology, surgery and oncology

New Insight into Immunity and Immunopathology of Rickettsial Diseases

Human rickettsial diseases comprise a variety of clinical entities caused by microorganisms belonging to the genera Rickettsia, Orientia, Ehrlichia, and Anaplasma. These microorganisms are characterized by a strictly intracellular location which has, for long, impaired their detailed study. In this paper, the critical steps taken by these microorganisms to play their pathogenic roles are discussed in detail on the basis of recent advances in our understanding of molecular Rickettsia-host interactions, preferential target cells, virulence mechanisms, three-dimensional structures of bacteria effector proteins, upstream signalling pathways and signal transduction systems, and modulation of gene expression. The roles of innate and adaptive immune responses are discussed, and potential new targets for therapies to block host-pathogen interactions and pathogen virulence mechanisms are considered

The “Lazio advice” telemedicine platform. First results of general practitioners’ usage, facilitators and barriers in the local health authority Roma 1

Background: Telemedical approaches represent a valuable tool for the management of coronavirus disease 2019 patients, allowing daily clinical assessment, monitoring of vital parameters, remote visits, and prescription of treatment or hospital ization in case of clinical worsening. This cross-sectional study aims to evaluate the use, barriers and facilitators of the “Lazio ADVICE” telemedical platform, a regional system for remote assistance for coronavirus disease 2019 patients at home, according to General Practitioners and Family Pediatricians of the Local Health Authority Roma 1, during the coronavirus disease 2019 pandemic. Methods: An interview-based survey was performed between December 2020 and January 2021. The survey investigated the demographic information of General Practitioner and Family Pediatricians, the knowledge of the platform, frequency of util ization, usefulness, strengths and weaknesses, and hypothesis of future implementation proposed. Results: We interviewed 214 physicians and 89 (41.6%) were classified as users and 125 (58.4%) as non-users. Older age and working in District 1, 14 and 15 (vs. District 13) significantly reduced the probability of using the platform physician. Among the 89 users, 19 (21.3%) used the platform every day or even several times a day, 40 (44.9%) several times a week but less than one access per day, 30 (33.7%) used the platform several times a month up to one entry per week. Most of them (92.3%) consider the platform useful. Barriers were poor integration with software and work routine (76.4%), and usability issues (53.9%). Among the 125 non-users, 14 (11.2%) didn’t know the existence of the platform, 60 (48.0%) never tried it and 51 (40.8%) tried to use it. Reported reasons for the interruption of use were not very user friendly (45.1%), perceived useless (37.3%), non-optimal functioning (23.5%), and lack of time (19.6%). Conclusion: The pandemic accelerated the implementation of telemedicine services around Lazio Region, starting a positive and continuous exchange of experiences, activities and best practices among physicians