Occupational low-dose irradiation and cancer risk among medical radiation workers.

BACKGROUND: Medical workers are the largest group of workers occupationally exposed to low doses of ionizing radiation (IR) worldwide. AIMS: This review presents all the cohorts of medical workers exposed in the world and summarizes cancer risks associated with radiation exposure in this population. METHODS: Epidemiological studies on health professionals exposed to IR published from 1975 to 2019 were reviewed. Strength of evidence was assessed according to the modified Royal College of General Practitioners three-star system. RESULTS: Among the 16 epidemiological studies focusing on cancers from 11 cohorts among medical staff exposed to radiation, higher risks of cancer were observed for pre-1950 exposure and for medical workers who performed fluoroscopically guided interventional procedures or radionuclides procedures compared to those who did not. However, strength of evidence supporting the associations remains moderate as several methodological limits including the lack of dosimetry data, lifestyle factors and recent updates may obscure the link between medical occupational exposure and cancer occurrence. CONCLUSIONS: Excess risk of cancer is suspected for high and former exposures. The more highly exposed professions, i.e. interventional physicians and nuclear medicine workers, should be monitored carefully. Collaborative projects aiming to increase the quantity and quality of information of the studied populations would be a key point.

Intergenerational effects of ionizing radiation: review of recent studies from human data (2018-2021).

PURPOSE: The purpose of this paper was to conduct a review of the studies published between 2018 and 2022 to investigate radiation-related effects in the offspring of human individuals exposed to ionizing radiation. METHODS: The search identified 807 publications, from which 9 studies were selected for detailed analysis to examine for effects in children whose parents were exposed to various types and doses of radiation. RESULTS: The review does not yield substantial evidence supporting intergenerational effects of radiation exposure in humans. However, caution is required when interpreting the results due to limitations in the majority of the published articles. CONCLUSION: This review, covering the period 2018-2022, serves as an extension of the previous systematic review conducted by Stephens et al. (2024), which encompassed the years 1988-2018. Together, these two papers offer a comprehensive overview of the available evidence regarding the intergenerational effects of parental pre-conceptional exposure to ionizing radiation. Overall, the findings do not provide strong evidence supporting a significant association between adverse (or other) outcomes in unexposed children and parental preconception radiation exposure.

Consideration of hereditary effects in the radiological protection system: evolution and current status.

PURPOSE: The purpose of this paper is to provide an overview of the methodology used to estimate radiation genetic risks and quantify the risk of hereditary effects as outlined in the ICRP Publication 103. It aims to highlight the historical background and development of the doubling dose method for estimating radiation-related genetic risks and its continued use in radiological protection frameworks. RESULTS: This article emphasizes the complexity associated with quantifying the risk of hereditary effects caused by radiation exposure and highlights the need for further clarification and explanation of the calculation method. As scientific knowledge in radiation sciences and human genetics continues to advance in relation to a number of factors including stability of disease frequency, selection pressures, and epigenetic changes, the characterization and quantification of genetic effects still remains a major issue for the radiological protection system of the International Commission on Radiological Protection. CONCLUSION: Further research and advancements in this field are crucial for enhancing our understanding and addressing the complexities involved in assessing and managing the risks associated with hereditary effects of radiation.

[Microscopic colitis: histopathological review with a clinicopathological correlation]. / Mikroskopische Kolitis: Histopathologische Übersicht mit klinisch-pathologischer Korrelation.

Microscopic colitis is a clinicopathological entity which, in addition to typical symptoms such as watery diarrhea, is characterized by its specific histopathology. Since colonoscopy yields normal findings, microscopic colitis belongs in a histological domain. The term encompasses two forms: lymphocytic and collagenous colitis. Histologically, lymphocytic colitis shows an increase in intraepithelial lymphocytes of more than 20 lymphocytes per 100 surface colonocytes, while collagenous colitis is characterized by a thickened subepithelial collagen layer of more than 10 µm. Specific stains help in the quantification of both. Since microscopic colitis does not always affect the entire colon and the number of intraepithelial lymphocytes varies physiologically, obtaining stepwise biopsies of the colon (with information on location where possible) is recommended. A thickened collagen layer is relatively specific for collagenous colitis, whereas intraepithelial lymphocytosis is also found in other diseases. Therefore, to make a correct diagnosis, it is important to correlate histological findings with clinical symptoms, including the main symptom of watery diarrhea.

Assessment of natural and synthetic wollastonite as source for bioceramics preparation.

Pseudowollastonite ceramics (beta-CaSiO3) from synthetic and natural sources were assessed with regard to their properties relevant to biomedical applications. Synthetic and natural CaSiO3 powders, with average particle size of 1.6 and 13.2 microm, respectively, were first employed. Powders were pressed and sintered at 1400 degrees C for 2 h. Pseudowollastonite was the only crystalline phase in sintered materials. Glassy phase, eight times more abundant in sintered natural wollastonite (SNW) than in the synthetic one (SSW), was observed in grain boundaries and in triple points. Larger grains and bigger and more abundant pores were present in SNW, resulting in lower diametral tensile strength (26 MPa), than in SSW (42 MPa). However, by milling the natural wollastonite starting powder to a particle size of 2.0 microm and sintering (SNW-M), the microstructure became finer and less porous, and diametral tensile strength increased (48 MPa). Weibull modulus of SNW and SNW-M samples was twice that of the SSW. All the samples released Si and Ca ions, and removed phosphate ions from simulated body fluid in similar amounts and were completely coated by apatite-like spherules after soaking in simulated body fluid for 3 wk. The aqueous extracts from all samples studied were not cytotoxic in a culture of human fibroblastic cells. No differences in fibroblast-like human cells adhesion and proliferation were observed between samples. According to the obtained results, properly processed pseudowollastonite bioceramics, obtained from the natural source, exhibit the same in vitro behavior and better performance in terms of strength and reliability than do the more expensive synthetic materials.

Interaction of per 3,6-anhydro-alpha cyclodextrins (alpha 36CD) and lead-alpha 36CD complex with biological systems.

The interactions of per (3,6 anhydro) alpha cyclodextrin (alpha 36CD) and of lead-alpha 36CD complex with biological systems were tested by NMR, ESR and electronic microscopy using erythrocytes and model membranes. It was found that the haemolytic activity of alpha 36CD alone was seven fold lower than that of natural alpha cyclodextrin (evaluated by the concentration inducing 50% haemolysis, DH50 = 35 mM). Conversely, the formation of the complex resulted in an increase of haemolytic properties, with DH50 of 1 mM. The mechanism proposed was an increased membrane diffusion by endocytosis of the complex, leading to higher amounts of intracellular lead.

[Glycopeptide-resistant Enterococcus outbreak in an ICU with simultaneous circulation of two different clones]. / Epidémie en réanimation médicochirurgicale d'Enterococcus faecium résistants aux glycopeptides (ERG) avec cocirculation de deux clones différents.

AIM OF THE STUDY: To describe specific difficulties to control a glycopeptide-resistant Enterococcus (GRE) outbreak occurring in an intensive care unit (ICU) during a regional epidemy. PATIENTS AND METHODS: Following identification of a GRE clinical isolate in ICU, systematic screening was performed on admission and then weekly, by anal swabs. GRE carriers were isolated according to two processes: first (week [W] 2-W8), cohorting of carriers in a dedicated sector of the ICU, with dedicated HCW; this required closing four of the 16 ICU beds. Second (W8-W29), a specific unit was created outside the ICU. VanA-genotypes and pulsed-field gel electrophoresis (PFGE) profiles were analyzed. RESULTS: During the first outbreak period (102 rectal swabs), two patients were found colonized at admission: the index case transferred from Nancy hospital, carrier of the Nancy epidemy PFGE profile strain, and one patient from the haemodialysis unit, carrier of a GRE strain presenting a different PFGE profile called the Thionville strain. Seven patients were newly identified as GRE colonized (2 by the Nancy strain and 5 by the Thionville strain). Defective running of the ICU was noted. During the second period (442 samples), six ICU patients were found colonized, including four at admission. No other case was identified in 16 weeks. Outbreak extension to other hospital units was checked at W19. The Thionville strain was not found in other regional hospitals. CONCLUSION: ICUs concentrate GRE colonization risk. This study demonstrates interest of PFGE. These low virulence bacteria have few direct pathological consequences, but they cause organizational problems in ICUs.

[Castleman's disease]. / Morbus Castleman. Seltene Differenzialdiagnose einer submandibulären Schwellung.

CASE REPORT: A 25-year-old patient with fever, dysphagia, and reduced general condition was referred to our department by his dentist after 1 week of antibiotic therapy. He presented with a painful palpable mass in the right lower jaw that had developed 2 weeks before. The orthopantomogram showed a caries and periapical lesion at the right lower wisdom tooth. During extraction of the tooth and putative intra- and extraoral abscess incision, no pus could be drained and the mass persisted. CT scans then revealed lobulated soft tissue masses on both sides of the neck with the main focus on the right side. In an additional operation with excision of the mass, Castleman's disease of the hyaline vascular type was diagnosed. HISTOPATHOLOGIC FINDINGS: Staging could not detect further pathological findings and the patient's postoperative general condition improved continuously. The histological features of the hayline vascular type of Castleman's disease were characterized by multiple germinal centers surrounded by circumferentially arranged layers of small lymphocytes interconnected by a prominent vascular stroma with occasional plasma cells ("onion skin"). CONCLUSION: Castleman's disease is a rare and yet poorly understood disease, characterized by inhomogeneous growth of lymphoid tissue. Mostly benign it remains a diagnostic challenge before histological investigation. In unclear submandibular swellings and neck lumps assumed to be an abscess, this rare differential diagnosis must be considered. Facing recurrence and potential for malignancy, follow-up of the patients over several years is necessary.