Typical values of z-resolution for different Digital Breast Tomosynthesis systems evaluated in a multicenter study.

PURPOSE: The aim of the present study, conducted by a working group of the Italian Association of Medical Physics (AIFM), was to define typical z-resolution values for different digital breast tomosynthesis (DBT) models to be used as a reference for quality control (QC). Currently, there are no typical values published in internationally agreed QC protocols. METHODS: To characterize the z-resolution of the DBT models, the full width at half maximum (FWHM) of the artifact spread function (ASF), a technical parameter that quantifies the signal intensity of a detail along reconstructed planes, was analyzed. Five different commercial phantoms, CIRS Model 011, CIRS Model 015, Modular DBT phantom, Pixmam 3-D, and Tomophan, were evaluated on reconstructed DBT images and 82 DBT systems (6 vendors, 9 models) in use at 39 centers in Italy were involved. RESULTS: The ASF was found to be dependent on the detail size, the DBT angular acquisition range, the reconstruction algorithm and applied image processing. In particular, a progressively greater signal spread was observed as the detail size increased and the acquisition angle decreased. However, a clear correlation between signal spread and angular range width was not observed due to the different signal reconstruction and image processing strategies implemented in the algorithms developed by the vendors studied. CONCLUSIONS: The analysis led to the identification of typical z-resolution values for different DBT model-phantom configurations that could be used as a reference during a QC program.

Clinical characteristics of and outcomes for patients with COVID-19 and comorbid lung diseases primarily hospitalized in a conventional pulmonology unit: A retrospective study.

BACKGROUND: Scant data are currently available about a potential link between comorbid chronic lung diseases (CLD) and the risk and severity of the coronavirus disease 2019 (COVID-19) infection. METHODS: To describe the clinical characteristics of and outcomes for patients with COVID-19 infection, including patients with comorbid respiratory diseases, who have been primarily hospitalized in the pulmonology department of Strasbourg University Hospital, France. In this retrospective, single-center study, we included all confirmed cases of COVID-19 from March 3 to April 15, 2020. We then compared the symptoms, biological and radiological findings, and outcomes for patients with and without CLD. RESULTS: Of the 124 patients that were enrolled, the median age was 62 years, and 75 patients (60%) were male. Overall, 40% of patients (n=50) had preexisting CLD, including chronic obstructive pulmonary disease (COPD) (n=15, 12%) and asthma (n=19, 15%). Twenty-eight patients were transferred to the intensive care unit (ICU), and six patients died in our unit. CLD were not predictive of ICU hospitalization, but a significantly higher total mortality was observed (17.6% vs. 5.5%, P<0.05) in these patients. CONCLUSIONS: Our results suggest the lack of an over-representation of CLD in COVID-19, representing 40% of patients in this cohort and even within a pulmonology department. CLD were not a risk factor for ICU management. However, a tendency to higher global mortality was observed in COVID-19 patients with CLD. Further studies are warranted to determine the risk of COVID-19 for patients with comorbid CLD.

Airway stent current practices evaluation: Survey among French bronchoscopy practitioners.

BACKGROUND: Airway stenting (AS) is performed for the treatment of benign or malignant central airway stenosis. In France, more than 30 centers practice AS. The aim of this survey was to evaluate the current practice around airway stenting among French bronchoscopy practitioners. METHOD: We performed an online survey sent to the GELF group (Groupe d'Endoscopie de Langue Française) mailing list. The first part comprised 10 questions about the different attitudes before AS and the second part included 10 questions about the management after AS. RESULTS: Thirty-six participants answered to the first part of the questionnaire and thirty-three to the second. There were some similarities, for example the absence of prophylactic antibiotic treatment before procedure (86%), use of saline nebulization, and removing or replacing the airway stent in case of persistent chest congestion or infection (73%). We also noted an important heterogeneity of the practices with several differences concerning systematic endoscopic control, bacteriological sampling before procedure (44%) and systematically AS replacement. CONCLUSION: This survey shows that AS management in France varies between practitioners. Respondents agreed on a few points, but disagreed on several important aspects of the management. These results emphasize the need of expert recommendations to improve AS management.

Acute Cardiac Failure Due to Takotsubo Cardiomyopathy Secondary to a Phone Call for Lung Transplantation: A Case Report.

Lung transplantation is a therapeutic option for certain end-stage lung diseases. The phone call for lung transplantation is a major event in the life of these patients; as a result, it can generate significant stress. We herein present the case of a 58-year-old female patient with end-stage chronic obstructive pulmonary disease (COPD) who, while on the lung transplantation waiting list, received such a call. Complete transplant work-up, including cardiac tests undertaken shortly before, had revealed no contraindication to lung transplantation. She was admitted with severe acute respiratory failure, and her extensive work-up was compatible with pulmonary edema due to takotsubo cardiomyopathy. The lung transplantation was thus cancelled, owing to the patient's health condition and the poor quality of the graft as well. The patient stayed in the intensive care unit for several days, requiring noninvasive ventilation. The left ventricular function recovered completely within 10 days postdiagnosis, and the patient was discharged 13 days after her admission. The patient was transplanted 1 month thereafter, without any particular problems; she is currently, 8 months post-transplantation, in good condition. In the given case, the call for lung transplantation could have generated emotional stress severe enough to lead to takotsubo cardiomyopathy.

D-IMRT verification with a 2D pixel ionization chamber: dosimetric and clinical results in head and neck cancer.

Dynamic intensity-modulated radiotherapy (D-IMRT) using the sliding-window technique is currently applied for selected treatments of head and neck cancer at Institute for Cancer Research and Treatment of Candiolo (Turin, Italy). In the present work, a PiXel-segmented ionization Chamber (PXC) has been used for the verification of 19 fields used for four different head and neck cancers. The device consists of a 32x32 matrix of 1024 parallel-plate ionization chambers arranged in a square of 24x24 cm2 area. Each chamber has 0.4 cm diameter and 0.55 cm height; a distance of 0.75 cm separates the centre of adjacent chambers. The sensitive volume of each single ionization chamber is 0.07 cm3. Each of the 1024 independent ionization chambers is read out with a custom microelectronics chip.The output factors in water obtained with the PXC at a depth of 10 cm were compared to other detectors and the maximum difference was 1.9% for field sizes down to 3x3 cm2. Beam profiles for different field dimensions were measured with the PXC and two other types of ionization chambers; the maximum distance to agreement (DTA) in the 20-80% penumbra region of a 3x3 cm2 field was 0.09 cm. The leaf speed of the multileaf collimator was varied between 0.07 and 2 cm s-1 and the detector response was constant to better than 0.6%. The behaviour of the PXC was measured while varying the dose rate between 0.21 and 1.21 Gy min-1; the mean difference was 0.50% and the maximum difference was 0.96%. Using fields obtained with an enhanced dynamic wedge and a staircase-like (step) IMRT field, the PXC has been tested for simple 1D modulated beams; comparison with film gave a maximum DTA of 0.12 cm. The PXC was then used to check four different IMRT plans for head and neck cancer treatment: cervical chordoma, parotid, ethmoid and skull base. In the comparison of the PXC versus film and PXC versus treatment planning system, the number of pixels with gamma parameter

Glass encapsulation of flavours with chemically modified starch blends.

Carrier compositions based on blends of various octenylsuccinic acid anhydride (OSAN)-modified starches were utilized in the glass encapsulation of flavours by means of melt extrusion and spray drying. Dextrinized, acid and enzymatically hydrolysed OSAN starches were used in various combinations. Processing parameters were optimized for desirable physical chemical and functional properties of the encapsulating compositions. One key property in the optimization of the extrusion process was setting rate of the exiting melt into a glass. Glassy states of identical spray-dried and extruded compositions were characterized by MDSC for glass transition temperature(s), heat capacity change and enthalpy relaxation. Flavour retention, surface flavour, moisture, particle density and flavour particle size distribution were also measured and compared for the extruded and spray-dried compositions. In addition, elastic recovery and caking were evaluated for extruded compositions. The glass transition parameters were correlated directly or indirectly with most of the physical properties of encapsulating compositions, especially flavour retention, surface flavour and caking. In extruded compositions, two phases were revealed by the presence of two glass transitions, whereas spray-dried compositions showed only one broad glass transition.

[Implants in partially edentulous patients with history of periodontal disease]. / Impianti in pazienti parzialmente edentuli con storia di malattia parodontale.

BACKGROUND: Microbiota associated with periodontal diseases were also associated with periimplant diseases. The purpose of this study was to determine the clinical status and composition of subgingival microbiota of implants and natural teeth in a group of partially edentulous patients with history of periodontal disease. METHODS: 38 partially edentulous patients with history of periodontal disease, treated with dental implants, were selected for this study. Patients selected for the study were in good health condition and did not take any antibiotics in the last six months. One year after second stage surgery a total of 72 implants and 38 teeth underwent clinical and microbiological examination. Clinical parameters were PD, PAL, PI and GI. Subgingival plaque samples were analyzed by dark-field microscopy and cultural analysis. RESULTS: Clinical parameters didn't show any significant differences between periodontal and periimplant tissues. Dark-field microscopic examination showed higher prevalence of rods and spirochetes around implants than around teeth. There were no differences detected by cultural examination in the subgingival microbiota at peri-implant and periodontal sites. CONCLUSIONS: Findings from this study showed no differences between implants and teeth in partially edentulous patients with history of periodontal disease one year after second stage surgery. Implants were colonized by microbiota similar to that observed around teeth and were well-maintained in patients with a history of periodontitis.

Hepatotoxicity of hydroxy-methyl-glutaryl-coenzyme A reductase inhibitors.

The first clinical studies on hydroxy-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors reported a low incidence of liver toxicity. The personal observation of a case of simvastatin-induced acute cholestatic hepatitis prompted us to evaluate the true incidence of hepatic side effects of these drugs in a large Italian population. One hundred patients taking simvastatin and ninety patients treated with pravastatin were followed-up six months with periodical evaluation of serum lipid levels and liver function test. In 5% of simvastatin-treated patients and 4.5% of pravastatin-treated patients significant liver toxicity was observed, which required drug discontinuation. The mechanism of liver damage was direct, idiosyncratic, but immunological features of drug toxicity could be hypothesized in one patient.

M-line protein: Presence of two non-equivalent high molecular weight components.

M-line enriched protein preparations were prepared from glycerated rabbit muscle myofibrils by means of three alternate procedures and analysed with SDS-polyacrylamide gel electrophoresis. A doublet corresponding to polypeptides with molecular weights of 193,000 and 182,000 was obtained in a ratio of2:3, respectively. The two bands are evident in SDS-gels of purified myofibrils, indicating that the proteins represent intrinsic M-line structural peptides. Transmission electron micrographs of the extracted myofibrils confirmed the effectiveness of the extraction procedures for removing M-line proteins. The possible significance of the M-line proteins to meat science is discussed.

Instability of SDS-denatured proteins prepared from musle myofibrils.

Evidence is presented showing that myofibrils solubilised by sodium dodecyl sulphate undergo proteolysis upon being allowed to warm to room temperature overnight or on storage for several days at 0-4°C. Results indicate that the extra protein bands occurring under such conditions are due to the presence of an indigenous muscle protease(s). Modifications in the handling of samples are suggested in order to avoid these artifacts. The possible significance of the protease(s) to meat tenderness is briefly discussed.

Improved resolution of myofibrillar proteins with sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Standard experimental procedures for continuous polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate were modified to give more effective separation and improved resolution of myofibrillar proteins. The system utilizes a running gel consisting of 10% acrylamide with 0.1% bisacrylamide crosslinker (100:1) incorporating 400 mM Tris/glycine (pH 8.80), 0.1 mM ethylenediaminetetraacetate, 5% glycerol and 0.1% sodium dodecyl sulfate. Electrophoresis was performed at 1 mA per gel with corresponding running times of 4-6 h. The myosin heavy chain enters and migrates as a narrow symmetrical band while the smaller regulatory proteins of the myofibril are resolved. The utility of the procedure in relation to the study of protein structure is detailed.

Comparison of isolated sarcoplasmic reticulum from bovine and rabbit muscle.

Comparison of the ultrastructure of purified bovine sarcoplasmic reticulum (SR) vesicles isolated from bovine sternomandibularis muscle before and following cold shortening indicates that the decreased Ca(2+)-accumulating ability and increased release of Ca(2+) in cold shortened muscle are not associated with any apparent structural alterations. Sodium dodecyl sulphate (SDS)-gel profiles revealed that the major constituent in both bovine and rabbit SR was Ca(2+)-activated ATPase with a molecular weight of 100,000-105,000. Both SR preparations also showed a proteolipid band at a molecular weight of approximately 10,000. Purified rabbit SR contained three protein components with molecular weights of 75,000, 60,000 and 53,000, whereas bovine SR exhibited a series of five components with molecular weights of 80,000, 66,000, 63,000, 50,000 and 45,000. Although the functions of these isolated proteins were not determined, it is assumed that at least some of them bind Ca(2+) ions in the SR.

Isolation of an extracellular neutral proteinase from Pseudomonas fragi.

A single proteolytic enzyme (EC 3.4.4.-) was isolated from culture supernatants of Pseudomonas fragi with 20% yielded and 60-fold purification by means of stepwise DEAE-Sephadex batch adsorption, ammonium sulfate precipitation, gel filtration and DEAE-cellulose chromatography. The enzyme was Zn-2+ activated and Ca-2+ stabilized, had optimum activity at pH 6.5--8.0 and 40 degrees C. The molecular weight range was 40 000--50 000 as determined by dodecylsulfate gel electrophoresis, gel filtration and Zn assay. This proteinase has properties similar to other extracellular bacterial neutral proteinases.