[Interprofessional recommendations on behalf of Société française de radiothérapie oncologique for the prevention, protection and management of cyberattacks in radiation oncology]

Cybersecurity is currently a major issue. Large hospitals are no longer the only main targets of attacks, but all healthcare organizations and establishments, without distinction of size or activities. The information system is defined as all the resources needed to collect images, store and process them with general distribution of multiple information within an organization. Systems are therefore crucial for the functioning of a medical department. Radiation oncology is one of the specialties most dependent on digital resources, for imaging, data transfer, dosimetry, treatment and so on.. Radiation oncology departments are therefore a prime target for ransomware attacks, which have increased significantly in recent years. Cybersecurity can be likened to a viral or bacterial attack. It is based on the two usual pillars of antimicrobial protection : hygiene and prophylaxis. In this article, we will detail by analogy the three classic levels of prevention of a bacillary attack: "primary prevention", which acts upstream of the infection; "secondary prevention", which acts at an early stage of its evolution; and "tertiary prevention", which acts on complications and risks of recurrence. This article is the result of an interprofessional group on behalf of SFRO, the French society of radiation oncology, with the aim of helping all teams to implement safety adapted to the specificities of a radiation oncology department in France.

Passage of uranium through human cerebral microvascular endothelial cells: influence of time exposure in mono- and co-culture in vitro models

PURPOSE

Depleted uranium (DU) has several civilian and military applications. The effects of this emerging environmental pollutant on human health raise some concerns. Previous experimental studies have shown that uranium (U) exposure can disturb the central nervous system. A small quantity of U reaches the brain via the blood, but the effects on the blood-brain barrier (BBB) remain unclear.

MATERIALS AND METHODS

In the present work, two cell culture models were exposed to DU for different times to study its cytotoxicity, paracellular permeability and extracellular concentration of U. The well-known immortalized human cerebral microvascular endothelial cells, hCMEC/D3, were cultured on the filter in the first model. In the second model, human primary cells of pericytes were cultured under the filter to understand the influence of cell environment after U exposure.

RESULTS

The results show that U is not cytotoxic to hCMEC/D3 cells or pericytes until 500 µM (1.6 Bq.L^-1). In addition, acute or chronic low-dose exposure of U did not disturb permeability and was conserved in both cell culture models. However, U is able to reach the brain compartment. During the first hours of exposure, the passage of U to the abluminal compartment was significantly reduced in the presence of pericytes. Electronic microscopy studies evidenced the formation of needlelike structures, like urchin-shaped precipitates, from 1 h of exposure. Analytical microscopy confirmed the U composition of these precipitates. Interestingly, precipitated U was detected only in endothelial cells and not in pericytes. U was localized in multilamellar or multivesicular bodies along the endo-lysosomal pathway, suggesting the involvement of these traffic vesicles in U sequestration and/or elimination.

CONCLUSIONS

We show for the first time the in vitro passage of U across a human cerebral microvascular endothelial cells, and the intracellular localization of U precipitates without any cytotoxicity or modification of paracellular permeability. The difference between the results obtained with monolayers and co-culture models with pericytes illustrates the need to use complex in vitro models in order to mimic the neurovascular unit. Further in vivo studies should be performed to better understand the passage of U across the blood-brain barrier potentially involved in behavioral consequences.

Development of whole brain versus targeted dentate gyrus irradiation model to explain low to moderate doses of exposure effects in mice

Evaluation of the consequences of low to moderate doses of ionizing radiation (IR) remains a societal challenge, especially for children exposed to CT scans. Appropriate experimental models are needed to improve scientific understanding of how exposure of the postnatal brain to IR affects behavioral functions and their related pathophysiological mechanisms, considering brain complex functional organization. In the brain, the dorsal and ventral hippocampal dentate gyrus can be involved in distinct major behavioral functions. To study the long term behavioral effects of brain exposure at low to moderate doses of IR (doses range 0.25–1 Gy), we developed three new experimental models in 10-day-old mice: a model of brain irradiation and two targeted irradiation models of the dorsal and ventral dentate gyrus. We used the technological properties of the SARRP coupled with MR imaging. Our irradiation strategy has been twofold endorsed. The millimetric ballistic specificity of our models was first validated by measuring gamma-H2AX increase after irradiation. We then demonstrated higher anxiety/depressive-like behavior, preferentially mediate by the ventral part of the dentate gyrus, in mice after brain and ventral dentate gyrus IR exposure. This work provides new tools to enhance scientific understanding of how to protect children exposed to IR.

Intracellular uranium distribution: Comparison of cryogenic fixation versus chemical fixation methods for SIMS analysis

Localization of uranium within cells is mandatory for the comprehension of its cellular mechanism of toxicity. Secondary Ion Mass Spectrometry (SIMS) has recently shown its interest to detect and localize uranium at very low levels within the cells. This technique requires a specific sample preparation similar to the one used for Transmission Electronic Microscopy, achieved by implementing different chemical treatments to preserve as much as possible the living configuration uranium distribution into the observed sample. This study aims to compare the bioaccumulation sites of uranium within liver or kidney cells after chemical fixation and cryomethods preparations of the samples: SIMS analysis of theses samples show the localization of uranium soluble forms in the cell cytoplasm and nucleus with a more homogenous distribution when using cryopreparation probably due to the diffusible portion of uranium inside the cytoplasm.

Chronic Exposure to External Low-Dose Gamma Radiation Induces an Increase in Anti-inflammatory and Anti-oxidative Parameters Resulting in Atherosclerotic Plaque Size Reduction in ApoE-/- Mice

Populations living in radiation-contaminated territories, such as Chernobyl and Fukushima, are chronically exposed to external gamma radiation and internal radionuclide contamination due to the large amount of ¹³⁷Cs released in the environment. The effect of chronic low-dose exposure on the development of cardiovascular diseases remains unclear. Previously reported studies have shown that low-dose radiation exposure could lead to discrepancies according to dose rate. In this study, we examined the effect of very low-dose and dose-rate chronic external exposure on atherosclerosis development. ApoE^-/- mice were chronically irradiated with a gamma source for 8 months at two different dose rates, 12 and 28 μGy/h, equivalent to dose rates measured in contaminated territories, with a cumulative dose of 67 and 157 mGy, respectively. We evaluated plaque size and phenotype, inflammatory profile and oxidative stress status. The results of this study showed a decrease in plaque sizes and an increase in collagen content in ApoE^-/- mice exposed to 28 μGy/h for 8 months compared to nonexposed animals. The plaque phenotype was associated with an increase in anti-inflammatory and anti-oxidative gene expression. These results suggest that chronic low-dose gamma irradiation induces an upregulation of organism defenses leading to a decrease in inflammation and plaque size. To our knowledge, this is the first study to describe the possible effect of chronic external very low-dose ionizing radiation exposure for 8 months. This work could help to identify the potential existence of a dose threshold, below that which harmful effects are not exhibited and beneficial effects are potentially observed. Furthermore, these findings permit consideration of the importance of dose rate in radiation protection.

DNA methylation and potential multigenerational epigenetic effects linked to uranium chronic low-dose exposure in gonads of males and females rats

INTRODUCTION

An increased health problem in industrialised countries is the contemporary concern of public and scientific community as well. This has been attributed in part to accumulated environmental pollutants especially radioactive substances and the use of nuclear power plants worldwide. However, the outcome of chronic exposure to low doses of a radionuclide such as uranium remains unknown. Recently, a paradigm shift in the perception of risk of radiotoxicology has emerged through investigating the possibility of transmission of biological effects over generations, in particular by epigenetic pathways. These processes are known for their crucial roles associated with the development of several diseases.

OBJECTIVE

The current work investigates the epigenetic effect of chronic exposure to low doses of uranium and its inheritance across generations. Materials and Methods To test this proposition, a rodent multigenerational model, males and females, were exposed to a non-toxic concentration of uranium (40mgL^-1 drinking water) for nine months. The uranium effects on were evaluated over three generations (F0, F1 and F2) by analysing the DNA methylation profile and DNMT genes expression in ovaries and testes tissues.

RESULTS

Here we report a significant hypermethylation of testes DNA (p <0.005) whereas ovaries showed hypomethylated DNA (p <0.005). Interestingly, this DNA methylation profile was significantly maintained across generations F0, F1 and F2. Furthermore, qPCR results of both tissues imply a significant change in the expression of DNA methyltransferase genes (DNMT 1 and DNMT3a/b) as well.

CONCLUSION

Altogether, our work demonstrates for the first time a sex-dependance and inheritance of epigenetic marks, DNA methylation, as a biological response to the exposure to low doses of uranium. However, it is not clear which type of reproductive cell type is more responsive in this context.

A prospective, randomized, multicenter comparative study of clinafloxacin versus a ceftriaxone-based regimen in the treatment of hospitalized patients with community-acquired pneumonia

In an open-label, phase 3, randomized, multicenter study, clinafloxacin (200 mg/d) was compared to ceftriaxone (2 g/d; with or without erythromycin) in 527 patients with acute community-acquired bacterial pneumonia (CAP). Primary efficacy parameters were clinical cure rate and microbiologic eradication rates (by pathogen and by patient) determined 5-9 d post-therapy (test of cure; TOC). Clinical cure rates at TOC for the 2 treatment groups were equivalent in the intention-to-treat (clinafloxacin 79.3, ceftriaxone 78.6%), clinically evaluable (clinafloxacin 88.1, ceftriaxone 85.0%), modified intention-to-treat (clinafloxacin 82.6, ceftriaxone 86.9%) and microbiologically evaluable populations (clinafloxacin 86.2, ceftriaxone 86.2%). Microbiologic eradication rates were similar in the 2 treatment groups. Both drugs were tolerated. Treatment of hospitalized CAP patients with clinafloxacin is a reasonable choice, especially when a resistant pathogen is anticipated.

Open-label, multicentre, emergency-use study of clinafloxacin (CI-960) in the treatment of patients with serious life-threatening infections

In an open-label emergency-use study, 23 patients with bacterial infections caused by multiply drug resistant pathogens were treated with clinafloxacin. Efficacy and safety were evaluated by tabulating investigators' assessments at the end of treatment, treatment discontinuations and adverse event data. Most of the patients were seriously ill and had multi-organ infections, primarily respiratory tract infections such as nosocomial pneumonia and gastrointestinal infections. Eleven patients were successfully treated, two had treatment failure and 10 were not evaluable because the patients died of their underlying disease. Considering that most of the patients had several infections caused by multiply resistant pathogens, clinafloxacin may be useful for the treatment of such life-threatening episodes.

Clinafloxacin monotherapy (CI-960) versus ceftazidime plus amikacin for empirical treatment of febrile neutropenic cancer patients

OBJECTIVE

To assess the efficacy and safety of clinafloxacin as a single agent for the empirical treatment of febrile episodes and bacterial infections in neutropenic cancer patients.

METHODS

An open label, active-controlled, randomized, parallel treatment, multicenter study was conducted where clinafloxacin monotherapy was compared to the combination of ceftazidime plus amikacin (plus optional vancomycin or teicoplanin). Four hundred and nineteen patients were randomized to receive either intravenous clinafloxacin 200 mg every 12 h or intravenous ceftazidime (2 g) iv every 8 h plus intravenous amikacin (15 mg/kg) per day in divided doses. All randomized patients were to receive a minimum of 48 h of primary study drug treatment, after which the primary treatment could be modified. Clinical and microbiological responses were evaluated at 7-21 days post-treatment after study treatment and long term (maximum 28 days), in intent-to-treat and modified intent-to-treat populations.

RESULTS

Clinafloxacin and ceftazidime-amikacin were statistically equivalent for the 72-h defervescence rate, overall defervescence rate, time to defervescence, clinical success rate, by-pathogen microbiological eradication rate, and survival rate. Clinical cure was achieved in 84% (59/70) of patients who received clinafloxacin monotherapy. There were no significant differences between treatments in rates of adverse events or treatment discontinuation rates due to adverse events.

CONCLUSIONS

Clinafloxacin appears to be an appropriate agent for empirical treatment in febrile neutropenic cancer patients.

Results of a clinical trial of clinafloxacin versus imipenem/cilastatin for intraabdominal infections

OBJECTIVE

Clinafloxacin is a novel quinolone with wide activity against the plethora of microorganisms encountered in intraabdominal infections. This trial was performed to examine its clinical efficacy.

SUMMARY BACKGROUND DATA

Clinafloxacin is representative of a new class of quinolones with considerable antimicrobial activity resulting from their mechanisms of action and pharmacodynamics. There is, however, concern about specific potential toxicities, including photosensitivity.

METHODS

This prospective, randomized, double-blind trial was conducted to compare clinafloxacin with imipenem/cilastatin as adjuncts in the management of complicated intraabdominal infections.

RESULTS

Five hundred twenty-nine patients were included in the intent-to-treat population, with 312 meeting all criteria for the valid population. Patients with a wide range of infections were enrolled; perforated or abscessed appendicitis was the most common (approximately 50%). One hundred twenty-three of the 150 valid patients treated with clinafloxacin (82%) had successful outcomes, as did 130 of the 162 (80%) treated with imipenem. For the intent-to-treat groups, 219 of 259 patients treated with clinafloxacin (85%) had successful outcomes, as did 219 of 270 patients treated with imipenem/cilastatin (81%). Treatment failure occurred in 39 patients who underwent drainage. There were substantially more gram-negative organisms recovered from the patients with treatment failure who were initially treated with imipenem/cilastatin.

CONCLUSIONS

The results of this study clearly demonstrate the safety and efficacy of clinafloxacin in the treatment of a range of intraabdominal infections, and in patients with a broad range of physiologic disturbances.

Cefdinir vs. amoxicillin/clavulanic acid in the treatment of suppurative acute otitis media in children

An investigator-blinded, randomized, multicenter study was conducted to compare the efficacy and safety of cefdinir and amoxicillin/ clavulanate (amoxicillin/CA) in the treatment of pediatric patients with acute suppurative otitis media. Patients 6 months to 12 years of age were randomized in a 1:1:1 ratio to receive cefdinir 14 mg/kg once-daily, cefdinir 7 mg/kg b.i.d., or amoxicillin/CA 13.3 mg/kg t.i.d. Test-of-cure was determined 11 to 16 days posttherapy. Of the 752 patients who entered the study, 665 (88%) completed treatment and 595 (79%) were evaluable. Response rates in the three treatment groups were similar. Overall rates of adverse events were statistically lower in the cefdinir once-daily group than in the amoxicillin/CA group. Diarrhea was the most common adverse event in all treatment groups. Cefdinir given either once-daily or twice-daily is a safe and effective treatment for pediatric patients with acute suppurative otitis media.

T-cell lymphoma associated with natural killer-like T-cell reaction

We report a case of T-cell lymphoma showing in the peripheral blood (PB) exclusively T-lymphocytes with suppresser T-cell preponderance and a high percentage of natural killer (NK) marker positive cells by flow cytometry. A T-cell receptor (TCR) gene analysis of the PB leukocytes demonstrated rearrangements of TCRalpha, TCRbeta, and TCRgamma genes. Therefore, the phenotype and genotype appeared to be consistent with an NK-like T-cell leukemia/lymphoma. However, when the PB lymphocytes were separated by size, it was found that 80% of NK marker positive cells were in the smaller cell population, while the neoplastic cells were in the large cell gate. A diagnosis of T-cell lymphoma with reactive NK-like T-cells was finally confirmed by demonstrating the presence of both large atypical lymphoid cells and large granular lymphocytes (LGL) on PB smears. Although immunoperoxidase stain of bone marrow and colon showed positive T-cell markers in the tumor cell population, cytoplasmic granules could not be identified in tissue sections and, thus, a distinction between T-cell lymphoma and NK-like T-cell lymphoma could not be made by light microscopy until NK markers were studied. CD57 was demonstrated immunohistochemically in small lymphocytes but not in the large tumor cells in the colon. Electron microscopy, however, demonstrated LGL reaction to the lymphoma cells in the colonic biopsy. NK-like T-cell lymphoma usually carries a poorer prognosis than peripheral T-cell lymphoma, thus the distinction of these neoplasms is important. This study emphasizes that T-cell lymphoma may cause an LGL reaction or proliferation. If the lymphoma cells were of the same size as LGL, flow cytometric studies may have misled the diagnosis to NK-like T-cell-lymphoma.

Cefdinir versus amoxicillin/clavulanic acid in the treatment of suppurative acute otitis media in children

An investigator-blinded, randomized, multicenter study was conducted to compare the efficacy and safety of cefdinir and amoxicillin/clavulanate (amoxicillin/CA) in the treatment of pediatric patients with acute suppurative otitis media. Patients 6 months to 12 years of age were randomized in a 1:1:1 ratio to receive cefdinir 14 mg/kg once-daily, cefdinir 7 mg/kg b.i.d., or amoxicillin/CA 13.3 mg/kg t.i.d. Test-of-cure was determined 11 to 16 days post therapy. Of the 752 patients who entered the study, 665 (88%) completed treatment and 595 (79%) were evaluable. Response rates in the three treatment groups were similar. Overall rates of adverse events were statistically lower in the cefdinir once-daily group than in the amoxicillin/CA group. Diarrhea was the most common adverse event in all treatment groups. Cefdinir given either once-daily or twice-daily is a safe and effective treatment for pediatric patients with acute suppurative otitis media.

Effects of magnesium-aluminum hydroxide and calcium carbonate antacids on bioavailability of ofloxacin

The effects of 15- and 5-ml doses of magnesium-aluminum hydroxide (MAH) and calcium carbonate (CC) antacids, respectively, on the bioavailability of ofloxacin after single oral 400-mg doses of ofloxacin were investigated in a 32-subject, randomized, crossover, open-label study. On four separate occasions, subjects received ofloxacin alone or antacid 24 h before, 2 h before, or 2 h after ofloxacin administration (n = 16 for each antacid). CC administration had no significant effect on the rate and extent of ofloxacin absorption regardless of the timing of antacid administration. A small but significant negative effect of MAH administration 2 h before ofloxacin administration was noted as evidenced by area under the curve and peak concentration in plasma data. Simultaneous administration of ofloxacin with either antacid was not investigated in this study. It appears that MAH and CC antacids in the doses used in this study generally do not interfere in a clinically significant manner with the bioavailability of ofloxacin, provided that an interval of at least 2 h separates the administration of these products.