TOPAS simulation of photoneutrons in radiotherapy: accuracy and speed with variance reduction.

Objective. We provide optimal particle split numbers for speeding up TOPAS Monte Carlo simulations of linear accelerator (linac) treatment heads while maintaining accuracy. In addition, we provide a new TOPAS physics module for simulating photoneutron production and transport.Approach.TOPAS simulation of a Siemens Oncor linac was used to determine the optimal number of splits for directional bremsstrahlung splitting as a function of the field size for 6 MV and 18 MV x-ray beams. The linac simulation was validated against published data of lateral dose profiles and percentage depth-dose curves (PDD) for the largest square field (40 cm side). In separate simulations, neutron particle split and the custom TOPAS physics module was used to generate and transport photoneutrons, called 'TsPhotoNeutron'. Verification of accuracy was performed by comparing simulations with published measurements of: (1) neutron yields as a function of beam energy for thick targets of Al, Cu, Ta, W, Pb and concrete; and (2) photoneutron energy spectrum at 40 cm laterally from the isocenter of the Oncor linac from an 18 MV beam with closed jaws and MLC.Main results.The optimal number of splits obtained for directional bremsstrahlung splitting enhanced the computational efficiency by two orders of magnitude. The efficiency decreased with increasing beam energy and field size. Calculated lateral profiles in the central region agreed within 1 mm/2% from measured data, PDD curves within 1 mm/1%. For the TOPAS physics module, at a split number of 146, the efficiency of computing photoneutron yields was enhanced by a factor of 27.6, whereas it improved the accuracy over existing Geant4 physics modules.Significance.This work provides simulation parameters and a new TOPAS physics module to improve the efficiency and accuracy of TOPAS simulations that involve photonuclear processes occurring in high-Zmaterials found in linac components, patient devices, and treatment rooms, as well as to explore new therapeutic modalities such as very-high energy electron therapy.

OSNA Total Tumor Load for the Prediction of Axillary Involvement in Breast Cancer Patients: Should We use Different Thresholds According to the Intrinsic Molecular Subtype? MOTTO Study.

Aims: To assess the impact of the molecular subtype (MS) on the total number of CK19 mRNA copies in all positive SLN (TTL) threshold, to predict non-SLN affectation, and to compare 5 years progression-free survival (PFS) according to the risk of recurrence (ROR) group by PAM50. Methods: Cohort with infiltrating breast cancer with intra-operative metastatic SLN detected by one-step nucleic acid amplification (OSNA) assay who underwent subsequent ALND. Logistic regression was used to assess a possible interaction between TTL and MS(Triple Negative, Her-2-Enriched, Luminal A, or Luminal B), or hormone receptors (HR: positive or negative) by immunohistochemistry (IMH). Cox regression was used to compare PFS and OS in the 3 ROR groups (high, medium, or low). Results: TTL was predictive of non-SLN affectation in both univariate (OR [95% CI]: 1.72 [1.43, 2.05], P < .001) and multivariate (1.55 [95% CI: 1.04, 2.32], P = .030) models, but MS-IMH or HR-IMH, and their interactions with TTL were not (best multivariate model: HR + main effect OR 1.16 [95% CI: 0.18, 7.64], P = .874; interaction OR: 1.04 [0.7, 1.55], P = .835; univariate model: HR + main effect OR: 1.44 [95% CI: 0.85, 2.44], P = .180). PFS was lower in the high-risk ROR group (81.1%) than in the low-risk group (93.9%) (HR: 3.68 [95 CI: 1.70, 7.94], P < .001). Conclusions: our results do not provide evidence to support the utilization of subtype-specific thresholds for TTL values to make therapeutic decisions on the axilla. The ROR group was predictive of 5 years-PFS.

Biocatalyst developed with recovered iron-rich minerals enhances the biotransformation of SARS-CoV-2 antiviral drugs in anaerobic bioreactors.

The biotransformation of the SARS-CoV-2 antiviral drugs, ribavirin and tenofovir, was studied in methanogenic bioreactors. The role of iron-rich minerals, recovered from a metallurgic effluent, on the biotransformation process was also assessed. Enrichment of anaerobic sludge with recovered minerals promoted superior removal efficiency for both antivirals (97.4 % and 94.7 % for ribavirin and tenofovir, respectively) as compared to the control bioreactor lacking minerals, which achieved 58.5 % and 37.9 % removal for the same drugs, respectively. Further analysis conducted by liquid chromatography coupled to mass spectroscopy revealed several metabolites derived from the biotransformation of both antivirals. Interestingly, tracer analysis with 13CH4 revealed that anaerobic methane oxidation coupled to Fe(III) reduction occurred in the enriched bioreactor, which was reflected in a lower content of methane in the biogas produced from this system, as compared to the control bioreactor. This treatment proposal is suitable within the circular economy concept, in which recovered metals from an industrial wastewater are applied in bioreactors to create a biocatalyst for promoting the biotransformation of emerging pollutants. This strategy may be appropriate for the anaerobic treatment of wastewaters originated from hospitals, as well as from the pharmaceutical and chemical sectors.

Low-dose radiotherapy to the lungs using an interventional radiology C-arm fluoroscope: Monte Carlo treatment planning and dose measurements in a postmortem subject.

Objective.The goal of this study was to use Monte Carlo (MC) simulations and measurements to investigate the dosimetric suitability of an interventional radiology (IR) c-arm fluoroscope to deliver low-dose radiotherapy to the lungs.Approach.A previously-validated MC model of an IR fluoroscope was used to calculate the dose distributions in a COVID-19-infected patient, 20 non-infected patients of varying sizes, and a postmortem subject. Dose distributions for PA, AP/PA, 3-field and 4-field treatments irradiating 95% of the lungs to a 0.5 Gy dose were calculated. An algorithm was created to calculate skin entrance dose as a function of patient thickness for treatment planning purposes. Treatments were experimentally validated in a postmortem subject by using implanted dosimeters to capture organ doses.Main results.Mean doses to the left/right lungs for the COVID-19 CT data were 1.2/1.3 Gy, 0.8/0.9 Gy, 0.8/0.8 Gy and 0.6/0.6 Gy for the PA, AP/PA, 3-field, and 4-field configurations, respectively. Skin dose toxicity was the highest probability for the PA and lowest for the 4-field configuration. Dose to the heart slightly exceeded the ICRP tolerance; all other organ doses were below published tolerances. The AP/PA configuration provided the best fit for entrance skin dose as a function of patient thickness (R2 = 0.8). The average dose difference between simulation and measurement in the postmortem subject was 5%.Significance.An IR fluoroscope should be capable of delivering low-dose radiotherapy to the lungs with tolerable collateral dose to nearby organs.

Indications and results of sentinel lymph node biopsy in breast cancer: Changes observed in 2018 compared to 2012.

BACKGROUND AND OBJECTIVE: Over the last 15 years, breast cancer (BC) treatment has undergone numerous changes, which have also affected the indications for Sentinel Lymph Node Biopsy (SLNB) as well as the procedures depending on its outcome. The aim of this study is to compare the results of the SLNB carried out at our Center during 2012, when we stopped performing an axillary lymph node dissection (ALND) after the finding of a micrometastasis, with those conducted in 2018, when we started applying Z011 criteria. MATERIALS AND METHODS: We have performed a comparative retrospective observational study, including cN0 BC patients that underwent a SLNB in 2012 versus those that underwent this procedure in 2018. RESULTS: 174 patients from 2012 and 165 from 2018 were studied. We found significant differences between the two groups: in 2018 there were fewer lobular invasive cancers (14 vs 28) (P < .05), a smaller mean pathological size (P < .001), a higher proportion of HER2 and triple negative tumors (28 vs 49) (P < .01) and, finally, an increase in use of neoadjuvant treatments (42.0% vs 6.7%). Regarding axillary involvement, we observed a decrease in both the presence of a positive sentinel node (24.1% in 2018 vs 42.4% in 2012) (P < .0001) as well as in the proportion of ALND performed (12.6% in 2018 vs 21.2% in 2012) and the presence of positive non sentinel nodes after a ALND (59.1% vs74.3%) (ns) CONCLUSION: Although the 2018 cohort that underwent SLNB had more aggressive tumors, there were fewer positive SN and ALND performed. This is probably due to a more accurate radiological diagnosis with ultrasound, that enables to detect cN1 cases before surgery, and to the increasing use of neoadjuvant treatments that may downstage the axilla.

New bimetallic adsorbent material based on cerium-iron nanoparticles highly selective and affine for arsenic(V).

Bimetallic oxy(hydroxides) have gain great interest in water treatment systems based on adsorption processes. Their high OH groups density, in addition to inheriting the oxides properties make them highly promising adsorbents of anions. In this work, highly affine and selective bimetallic oxyhydroxides of cerium and iron (Ce:Fe-P's) for arsenic(V) were synthesized by implementing an assisted microwave methodology. The Ce:Fe-P's were characterized by various techniques (SEM, FTIR, XRD and XPS) and the As(V) adsorption capacity and kinetics as well as the effect of pH and the presence of coexisting anions were determined. The results showed that Ce:Fe-P's have an outstanding As(V) adsorption capacity (179.8 mg g-1 at Ce = 3 mg L-1) even at low concentrations (120 mg g-1 at Ce = 37 µg L-1). Moreover, the adsorption equilibrium was reached very fast, just in 3 min, with an adsorption rate of 0.123 mg min-1, that is, 80% of the initial As(V) concentration of 5 mg L-1 was removed in the first 3 min. The arsenic adsorption capacity decreased only up to 20% at pH above 7, attributed to electrostatic repulsions due to the adsorbent's pHPZC, which was 6.8. On the other hand, the arsenic adsorption capacity of Ce:Fe-P's decreased just 21% in the presence of 10 mg L-1 of each of the following competing anions: F-, Cl-, SO42-, NO3-, PO43- and CO32-, which usually coincide in contaminated water with As(V). Ce:Fe-P's has proven to be one of the most promising As(V) adsorbent materials reported so far in the literature, because it presented an outstanding adsorption capacity and at the same time a very fast adsorption speed. Furthermore, the pH and the concentration of coexisting anions caused little interference in the adsorption processes. Due to the above, the Ce:Fe-P's is already in the process of intellectual protection.

Monitoring of RAS mutant clones in plasma of patients with RAS mutant metastatic colorectal cancer.

PURPOSE: Some patients with histologically confirmed primary mCRC and mutated RAS reported undetectable RAS mutant clones in plasma after receiving anti-VEGF treatment. The aim was to prospectively assess it with its potential therapeutic implications. METHODS: RAS mutant genes in solid biopsy (before first-line treatment: FOLFOX/CAPOX + bevacizumab) were compared in liquid biopsy (before second-line treatment: panitumumab + FOLFIRI), using Idylla™ system. Discordant results between solid/liquid biopsies were assessed by the next-generation sequencing (NGS) test (solid/liquid biopsies). RESULTS: Twenty-three patients were assessed (seven had RAS mutant discrepancies between solid/liquid biopsies). The NGS test confirmed that 3/23 (13%) patients had undetectable RAS mutant clones in liquid biopsy and 3/23 (13%) presented discrepancies in solid biopsy (Idylla™ system vs. NGS test). CONCLUSION: Thirteen percentage of patients had undetectable RAS mutant clones in liquid biopsy after first-line treatment. However, some discrepancies between solid and liquid biopsies have been observed. These results suggest a need to improve accuracy of RAS analyses, especially in solid biopsies.

Monte Carlo simulations and phantom validation of low-dose radiotherapy to the lungs using an interventional radiology C-arm fluoroscope.

PURPOSE: To use MC simulations and phantom measurements to investigate the dosimetry of a kilovoltage x-ray beam from an IR fluoroscope to deliver low-dose (0.3-1.0 Gy) radiotherapy to the lungs. MATERIALS AND METHODS: PENELOPE was used to model a 125 kV, 5.94 mm Al HVL x-ray beam produced by a fluoroscope. The model was validated through depth-dose, in-plane/cross-plane profiles and absorbed dose at 2.5-, 5.1-, 10.2- and 15.2-cm depths against the measured beam in an acrylic phantom. CT images of an anthropomorphic phantom thorax/lungs were used to simulate 0.5 Gy dose distributions for PA, AP/PA, 3-field and 4-field treatments. DVHs were generated to assess the dose to the lungs and nearby organs. Gafchromic film was used to measure doses in the phantom exposed to PA and 4-field treatments, and compared to the MC simulations. RESULTS: Depth-dose and profile results were within 3.2% and 7.8% of the MC data uncertainty, respectively, while dose gamma analysis ranged from 0.7 to 1.0. Mean dose to the lungs were 1.1-, 0.8-, 0.9-, and 0.8- Gy for the PA, AP/PA, 3-field, and 4-field after isodose normalization to cover âˆ¼ 95% of each lung volume. Skin dose toxicity was highest for the PA and lowest for the 4-field, and both arrangements successfully delivered the treatment on the phantom. However, the dose distribution for the PA was highly non-uniform and produced skin doses up to 4 Gy. The dose distribution for the 4-field produced a uniform 0.6 Gy dose throughout the lungs, with a maximum dose of 0.73 Gy. The average percent difference between experimental and Monte Carlo values were -0.1% (range -3% to +4%) for the PA treatment and 0.3% (range -10.3% to +15.2%) for the 4-field treatment. CONCLUSION: A 125 kV x-ray beam from an IR fluoroscope delivered through two or more fields can deliver an effective low-dose radiotherapy treatment to the lungs. The 4-field arrangement not only provides an effective treatment, but also significant dose sparing to healthy organs, including skin, compared to the PA treatment. Use of fluoroscopy appears to be a viable alternative to megavoltage radiation therapy equipment for delivering low-dose radiotherapy to the lungs.

Spectral characterization of flash and high flux x-ray radiographic sources with a magnetic Compton spectrometer.

In this work, we present a new analysis method applied to revitalize permanent magnet Compton spectrometers used to measure photon energy spectra in the MeV range. The inversion of the measured electron distribution to determine the original photon distribution is achieved via a method of consistent coupled radiation transport and magnetic field mapping of the input photon spectra to the measured electron distribution. The method of linear least squares was used to perform the unfolding of the electron distribution to the initial photon spectra, without any assumptions made regarding the electron distribution. We present an application of this method to data from a nominal 19.4 MeV flash radiographic source (the first axis of the Dual Axis Radiographic Hydro-Test Facility) capable of generating 500 R @ 1 m in ∼60 ns and a medical therapy source (a Scanditronix M22, Microtron) capable of variable energies with nominal endpoints of 6, 10, 15, and 20 MeV and an output of ∼1000-2000 R/min @ 1 m. The results provide agreement between the modeled and unfolded experimentally measured photon spectra as quantified by statistical tests, from 1.5 to 20 MeV. Experimental results are presented as well as a discussion of the novel MCNP6-based simulations and methods for reconstruction of the spectra.

Report on G4-Med, a Geant4 benchmarking system for medical physics applications developed by the Geant4 Medical Simulation Benchmarking Group.

BACKGROUND: Geant4 is a Monte Carlo code extensively used in medical physics for a wide range of applications, such as dosimetry, micro- and nanodosimetry, imaging, radiation protection, and nuclear medicine. Geant4 is continuously evolving, so it is crucial to have a system that benchmarks this Monte Carlo code for medical physics against reference data and to perform regression testing. AIMS: To respond to these needs, we developed G4-Med, a benchmarking and regression testing system of Geant4 for medical physics. MATERIALS AND METHODS: G4-Med currently includes 18 tests. They range from the benchmarking of fundamental physics quantities to the testing of Monte Carlo simulation setups typical of medical physics applications. Both electromagnetic and hadronic physics processes and models within the prebuilt Geant4 physics lists are tested. The tests included in G4-Med are executed on the CERN computing infrastructure via the use of the geant-val web application, developed at CERN for Geant4 testing. The physical observables can be compared to reference data for benchmarking and to results of previous Geant4 versions for regression testing purposes. RESULTS: This paper describes the tests included in G4-Med and shows the results derived from the benchmarking of Geant4 10.5 against reference data. DISCUSSION: Our results indicate that the Geant4 electromagnetic physics constructor G4EmStandardPhysics_option4 gives a good agreement with the reference data for all the tests. The QGSP_BIC_HP physics list provided an overall adequate description of the physics involved in hadron therapy, including proton and carbon ion therapy. New tests should be included in the next stage of the project to extend the benchmarking to other physical quantities and application scenarios of interest for medical physics. CONCLUSION: The results presented and discussed in this paper will aid users in tailoring physics lists to their particular application.

Uso de Peróxido de Hidrógeno como Enjuague Bucal Previo a la Consulta Dental para Disminuir la Carga Viral de COVID-19. Revisión de la Literatura / Use of Hydrogen Peroxide as a Dental Pre-consultation Mouthwash to Decrease the Viral Load of COVID-19. Literature Review

RESUMEN: La utilización de enjuagues antisépticos previo a la atención odontológica favorecería la disminución del virus en la cavidad oral. Se ha planteado el uso de peróxido de hidrógeno preconsulta dental. Se revisaron las bases de datos PubMed, Cochrane y Elsevier publicados desde Enero 2019 a junio 2020. Los estudios que cumplieron los criterios de inclusión fueron revisados por 2 autores individualmente. Se realizó una revisión cualitativa de los datos. No existen ensayos controlados aleatorios o estudios de observación clínica sobre el efecto curativo o preventivo del peróxido de hidrógeno contra el COVID-19, pero si protocolos de ensayos clínicos que están en proceso de reclutamiento. El enjuague bucal con peróxido de hidrógeno podría ser una solución viable pre consulta dental que debe ser estudiada para reducir la carga viral del COVID-19.

ABSTRACT: The use of antiseptic rinses prior to dental care would favor the reduction of the virus in the oral cavity. The use of hydrogen peroxide prior to dental consultation has been proposed. PubMed, Cochrane and Elsevier databases published from January 2019 to June 2020 were reviewed. Studies that met the inclusion criteria were reviewed by 2 authors individually. A qualitative review of the data was performed. There are no randomized controlled trials or clinical observation studies on the curative or preventive effect of hydrogen peroxide against COVID-19, but there are clinical trial protocols that are in the process of recruitment. Hydrogen peroxide mouthwash could be a viable solution prior to dental consultation that should be studied, to reduce COVID-19 viral load.

Synthesis of Bamboo-like Multiwall Carbon Nanotube-Poly(Acrylic Acid-co-Itaconic Acid)/NaOH Composite Hydrogel and its Potential Application for Electrochemical Detection of Cadmium(II).

A poly(acrylic acid-co-itaconic acid) (PAA-co-IA)/NaOH hydrogel containing bamboo-type multiwall carbon nanotubes (B-MWCNTs) doped with nitrogen (PAA-co-IA/NaOH/B-MWCNTs) was synthesized and characterized by SEM, absorption of water, point of zero charges, infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The possible use of the PAA-co-IA/NaOH/B-MWCNT hydrogel as an electrode modifier and pre-concentrator agent for Cd(II) sensing purposes was then evaluated using carbon paste electrodes via differential pulse voltammetry. The presence of the B-MWCNTs in the hydrogel matrix decreased its degree of swelling, stabilized the structure of the swollen gel, and favored the detection of 3 ppb Cd(II), which is comparable to the World Health Organization's allowable maximum value in drinking water. A calibration curve was obtained in the concentration range of 2.67 × 10-8 to 6.23 × 10-7 M (i.e., 3 and 70 ppb) to determine a limit of detection (LOD) of 19.24 µgL-1 and a sensitivity of 0.15 µC ppb-1. Also, the Zn(II), Hg(II), Pb(II) and Cu(II) ions interfered moderately on the determination of Cd(II).

LET-Dependent Intertrack Yields in Proton Irradiation at Ultra-High Dose Rates Relevant for FLASH Therapy.

FLASH radiotherapy delivers a high dose (≥10 Gy) at a high rate (≥40 Gy/s). In this way, particles are delivered in pulses as short as a few nanoseconds. At that rate, intertrack reactions between chemical species produced within the same pulse may affect the heterogeneous chemistry stage of water radiolysis. This stochastic process suits the capabilities of the Monte Carlo method, which can model intertrack effects to aid in radiobiology research, including the design and interpretation of experiments. In this work, the TOPAS-nBio Monte Carlo track-structure code was expanded to allow simulations of intertrack effects in the chemical stage of water radiolysis. Simulation of the behavior of radiolytic yields over a long period of time (up to 50 s) was verified by simulating radiolysis in a Fricke dosimeter irradiated by 60Co γ rays. In addition, LET-dependent G values of protons delivered in single squared pulses of widths, 1 ns, 1 µs and 10 µs, were obtained and compared to simulations using no intertrack considerations. The Fricke simulation for the calculated G value of Fe3+ ion at 50 s was within 0.4% of the accepted value from ICRU Report 34. For LET-dependent G values at the end of the chemical stage, intertrack effects were significant at LET values below 2 keV/µm. Above 2 keV/µm the reaction kinetics remained limited locally within each track and thus, effects of intertrack reactions remained low. Therefore, when track structure simulations are used to investigate the biological damage of FLASH irradiation, these intertrack reactions should be considered. The TOPAS-nBio framework with the expansion to intertrack chemistry simulation provides a useful tool to assist in this task.

Plasmocitoma mamario y cáncer de mama: a propósito de un caso / Breast Plasmacytoma and breast cancer: a case report

El plasmocitoma mamario es una neoplasia de células plasmáticas extremadamente infrecuente, con menos de cincuenta casos descritos en el último siglo. Por este motivo, apenas se dispone de datos acerca del abordaje, tratamiento y seguimiento más convenientes. Presentamos el caso de una paciente de 70 años que debutó con un plasmocitoma mamario y que un año después fue diagnosticada de un carcinoma mamario lobulillar ipsilateral. La asociación entre plasmocitoma y cáncer de mama no está descrita en la literatura, por lo que es muy complicado establecer un vínculo entre ambas entidades. Sin embargo, el abordaje terapéutico del plasmocitoma podría comprometer el tratamiento ulterior de un cáncer de mama, por lo que el tratamiento idóneo en estos casos sea probablemente la cirugía.

Breast plasmocytoma is an extremely rare plasma cell neoplasm, with less than 50 cases reported in the last century. This is the reason why we barely have data about optimal management, treatment and follow-up. We hereby report the case of a 70 year old woman diagnosed with breast plasmocytoma that developed lobular breast cancer a year later. The link between plasmocytoma and breast cancer has not been previously established. However, breast plasmocytoma treatment could compromise latter breast cancer approach, so probably the most suitable strategy in these cases should be breast surgery.Conclusions: There are clinical characteristics associated with complications in women with surgical management abortion in our center, such as admission diagnosis, unplanned pregnancy, previous abortion and type of evacuation. There are limitations regarding the quantity and quality of information, however, our results allow us to know the profile of patients treated for abortion in our center.

Subclinical inflammation in the preclinical phase of rheumatoid arthritis might contribute to articular joint damage.

The first degree relatives of rheumatoid arthritis (RA) patients have a higher risk of developing RA, which is related to the expression of autoantibodies against citrullinated proteins (ACPA). Remarkably, prior to the onset of RA, cartilage damage is already initiated, whereas ACPA autoantibodies are already expressed. Here we show that both TNF-α and IL-6 are also increased prior to the onset of RA. Furthermore, when the levels of DKK1 and Sclerostin were evaluated in first degree relatives of RA patients, we found that the serum levels of TNF- α correlate with the expression levels of both DKK1 and Sclerostin. Interestingly, when the disease is already established, the correlation of TNF- α with DKK1 is lost in RA patients, whereas the correlation of Sclerostin with both TNF- α and IL-6 is further increased. Our data suggest a subclinical inflammation in patients at high risk of developing RA, which might lead to an increase in the levels of both DKK1 and Sclerostin, contributing to joint damage in the preclinical phase of the disease linked to the expression of ACPA autoantibodies.

Antibody-Mediated Rejection Treatment With Bortezomib in Renal Transplant Recipients: A Single-Center 24-Month Follow-up Case Report.

INTRODUCTION: Antibody-mediated rejection (AMR) is related to a poor prognosis in graft survival, with 27% to 40% of patients experiencing graft loss within the first year. The mechanism of damage in AMR is mediated by donor-specific antibodies (DSA). No standard treatment for AMR exists, and conventional management includes high doses of steroids, plasmapheresis, intravenous immunoglobulin, and either rituximab or bortezomib. Because of the high cost of these medications and the lack of prospective studies to evaluate their efficacy and safety, their routine use is limited. In the following study, we describe the use of bortezomib for the treatment of AMR in 5 renal transplant recipients with a 24-month follow-up and compare this case with the reviewed literature. MATERIAL AND METHODS: Five cases of AMR diagnosed by biopsy are reported, and these patients received bortezomib at a rate of 1.3 mg/m2 on days 1, 4, 8, and 11; plasmapheresis; and 1 patient received 30 g of intravenous immunoglobulin. RESULTS: All patients received his or her first transplant; 4 were from a cadaveric donor, and 1 patient received thymoglobulin at a standard dose. All patients had maintenance therapy based on cyclosporine, mycophenolate mofetil, and prednisone, with an average baseline creatinine level of 1.3 mg/dL. The average days until rejection event were 952 days. DISCUSSION AND CONCLUSION: AMR treatment with bortezomib was effective, showing stable renal function at 24 months. Patients had adequate tolerance for administration. So far, these results contrast with the literature reviewed, so additional studies and follow-up are required for a new evaluation.

Efecto de gas de formalina sobre el recuento de mesófilos en nailon comercial destinado a procedimientos quirúrgicos / Effect of formaline gas on the counting of mesophiles in commercial nylon destined to surgical procedures

RESUMEN La investigación se realizó a fin de evaluar el efecto del gas de formalina sobre el recuento de mesófilos en nailon comercial (poliamida) destinado a procedimientos quirúrgicos. En primer lugar, se evaluó la contaminación de una muestra del material comercial de 1 g expuesta al ambiente de quirófano por 72 horas, a través de la técnica de recuento en placa para mesófilos; se obtuvieron 850 UFC/g. Una vez comprobada la contaminación de la poliamida comercial, esta se sometió a gases de formalina en comprimidos. Se colocaron 5 muestras (n=5) de nailon de 1 g cada una en 5 recipientes herméticos de 1 litro con 1 gramo de formalina cada uno; estos recipientes se almacenaron en un mueble en sala de esterilización a un metro de altura del piso y posteriormente, fueron abiertos y cultivados a través de la técnica de recuento en placa para mesófilos, uno por día a lo largo de 5 días a intervalos de 24 horas. Los resultados obtenidos no registraron crecimientos de microorganismos a partir de las 24 horas y durante los 5 días posteriores y se encontraron diferencias estadísticamente significativas (p < 0,05). Se concluye que bajo las condiciones del presente estudio el tiempo de esterilización de la formalina sobre nailon comercial es de 24 horas.

ABSTRACT Hie present research work was carried out with the purpose of evaluating the effect of formalin gas on the count of mesophiles in commercial nylon (polyamide) destined to surgical procedures. Firstly, the contamination of a 1 g commercial nylon sample, exposed to the operating room environment for 72 hours, was evaluated through the plate counting technique for mesophiles; it yielded a result of 850 CFU / gram. Once the contamination of the commercial polyamide was checked, it was subjected to formalin gases in tablets. Five nylon samples (n=5) of 1 gram each were placed in 5 1 liter airtight containers containing 1 gram of formalin; Hese containers were stored in a cabinet in the sterilization room one meter above the floor, and later opened and cultivated through the plate counting technique for mesophiles, one per day for 5 days at 24 hour intervals. The results obtained after being exposed to formalin gases in tablets did not register growths of microorganisms after 24 hours and during the 5 days after the study, finding statistically significant differences (p < 0.05) in relation to the studied times concluding under the conditions of the present study that the sterilization time of the formalin on commercial nylon is equal to 24 hours.

Leptospirosis in an asplenic patient -case report.

BACKGROUND: The presentation of clinical leptospirosis has been historically associated with animal workers, slaughterhouse workers and medical veterinarians. This association has shifted to be related to flooding events and outdoor activities; few cases are related to high-risk factors found in immunosuppressed patients. Scarcely a handful of cases have serological evidence of immune response against Leptospira serovar Bratislava representing serogroup Australis, a serovar associated with poor reproductive performance in swine and horses, and recently with cats. CASE PRESENTATION: Herein, we describe a rare clinical presentation of disseminated Leptospira infection in an immunosuppressed 65-year-old woman. She was admitted to the emergency room with fever, bacteraemia, bilateral uveitis and pulmonary involvement. The patient denied outdoor activities; she only had wide exposure to faeces and urine from cats living in her home. Her medical history included idiopathic thrombocytopenic purpura (ITP) diagnosed at the age of 18. She did not respond to medical treatment, and a splenectomy was performed. At age 60, she was diagnosed with Chronic Myeloid Leukemia (CML), and was treated with a tyrosine kinase inhibitor (TKI) -Imatinib. The patient voluntarily discontinued the treatment for the last 6 months. After extensive workup, no microorganisms were identified by the commonly used stains in microbiology. The diagnosis was performed through dark-field microscopy, microagglutination test (MAT), Leptospira genus-specific PCR, the IS1500 PCR for identification of pathogenic species, and 16S based sequencing for the genus identification. CONCLUSION: Immunosuppressed patients may acquire uncommon infections from ubiquitous microorganisms. In this case, serology evidence of exposure to Leptospira serovar Bratislava by MAT and the presence of the Leptospira genus were identified. It should be on mind for the diagnosis in otherwise healthy patients, and thoroughly search on splenectomised patients exposed to animals. Additionally, this report highlights the usefulness of PCR for diagnosis of this potentially life-threatening illness.

[Trident sign in spinal cord neurosarcoidosis]. / Signo del tridente en la neurosarcoidosis medular.

TITLE: Signo del tridente en la neurosarcoidosis medular.

[High level of student smokers in Madrid compared with a similar previous study of 2014]. / Tabaquismo en los estudiantes de alto nivel académico en la Comunidad de Madrid y comparación con estudio previo similar realizado en 2014.

Smoking is a public health problem that affects young people, and influenced by the environment and cultural level. OBJECTIVES: To determine smoking prevalence among high-level baccalaureate students in the Autonomous Community of Madrid during the 2018-2019 academic year. To assess the influence of the socio-cultural environment on the onset of youth smoking. To compare the results with previous studies conducted on students of baccalaureate of excellence (BE) and the general population. POPULATION AND METHODS: Cross-sectional study on BE students in the Autonomous Community of Madrid. Using an anonymous questionnaire, they were asked about tobacco, alcohol and drug consumption, as well as the influence of the environment, friends, and family in the beginning. To compare with previous studies. RESULTS: A total of 740 valid questionnaires were collected, of which 430 (58.1%) were female, an overall mean age of 16.57±0.61 years, and 53 (7.18%) were smokers. The majority 39 (78%) of smokers acknowledged their friends' influence at its onset. Alcohol was consumed by 349 (47.48%) and other drugs by 109 (15.27%). Being a smoker was related to alcohol, other drugs, a smoking mother, smoking siblings and smoking friends. CONCLUSIONS: Smoking prevalence among students of BE in Autonomous Community of Madrid continues to be lower than the prevalence of adolescents of their age and there are no variations from previous reports. Starting smoking is related to smoking by friends, siblings, and the mother and with the consumption of alcohol and other substances. Education is very important in the beginning and prevention of smoking, and it is necessary to implement prevention programs at early ages in order to promote their effectiveness, and aimed at young people, parents and teachers.