The cytokinesis-block micronucleus assay on human isolated fresh and cryopreserved peripheral blood mononuclear cells

The cytokinesis-block micronucleus (CBMN) assay is a standardized method used for genotoxicity studies. Conventional whole blood cultures (WBC) are often used for this assay, although the assay can also be performed on isolated peripheral blood mononuclear cell (PBMC) cultures. However, the standardization of a protocol for the PBMC CBMN assay has not been investigated extensively. The aim of this study was to optimize a reliable CBMN assay protocol for fresh and cryopreserved peripheral blood mononuclear cells (PBMCS), and to compare micronuclei (MNi) results between WBC and PBMC cultures. The G(0)CBMN assay was performed on whole blood, freshly isolated, and cryopreserved PBMCS from healthy human blood samples and five radiosensitive patient samples. Cells were exposed to 220 kV X-ray in vitro doses ranging from 0.5 to 2 Gy. The optimized PBMC CBMN assay showed adequate repeatability and small inter-individual variability. MNi values were significantly higher for WBC than for fresh PBMCS. Additionally, cryopreservation of PBMCS resulted in a significant increase of MNi values, while different cryopreservation times had no significant impact. In conclusion, our standardized CBMN assay on fresh and cryopreserved PBMCS can be used for genotoxicity studies, biological dosimetry, and radiosensitivity assessment

Children’s and adolescents’ rising animal-source food intakes in 1990–2018 were impacted by age, region, parental education and urbanicity

Animal-source foods (ASF) provide nutrition for children and adolescents’ physical and cognitive development. Here, we use data from the Global Dietary Database and Bayesian hierarchical models to quantify global, regional and national ASF intakes between 1990 and 2018 by age group across 185 countries, representing 93% of the world’s child population. Mean ASF intake was 1.9 servings per day, representing 16% of children consuming at least three daily servings. Intake was similar between boys and girls, but higher among urban children with educated parents. Consumption varied by age from 0.6 at <1 year to 2.5 servings per day at 15–19 years. Between 1990 and 2018, mean ASF intake increased by 0.5 servings per week, with increases in all regions except sub-Saharan Africa. In 2018, total ASF consumption was highest in Russia, Brazil, Mexico and Turkey, and lowest in Uganda, India, Kenya and Bangladesh. These findings can inform policy to address malnutrition through targeted ASF consumption programmes.publishedVersio

Incident type 2 diabetes attributable to suboptimal diet in 184 countries

The global burden of diet-attributable type 2 diabetes (T2D) is not well established. This risk assessment model estimated T2D incidence among adults attributable to direct and body weight-mediated effects of 11 dietary factors in 184 countries in 1990 and 2018. In 2018, suboptimal intake of these dietary factors was estimated to be attributable to 14.1 million (95% uncertainty interval (UI), 13.8–14.4 million) incident T2D cases, representing 70.3% (68.8–71.8%) of new cases globally. Largest T2D burdens were attributable to insufficient whole-grain intake (26.1% (25.0–27.1%)), excess refined rice and wheat intake (24.6% (22.3–27.2%)) and excess processed meat intake (20.3% (18.3–23.5%)). Across regions, highest proportional burdens were in central and eastern Europe and central Asia (85.6% (83.4–87.7%)) and Latin America and the Caribbean (81.8% (80.1–83.4%)); and lowest proportional burdens were in South Asia (55.4% (52.1–60.7%)). Proportions of diet-attributable T2D were generally larger in men than in women and were inversely correlated with age. Diet-attributable T2D was generally larger among urban versus rural residents and higher versus lower educated individuals, except in high-income countries, central and eastern Europe and central Asia, where burdens were larger in rural residents and in lower educated individuals. Compared with 1990, global diet-attributable T2D increased by 2.6 absolute percentage points (8.6 million more cases) in 2018, with variation in these trends by world region and dietary factor. These findings inform nutritional priorities and clinical and public health planning to improve dietary quality and reduce T2D globally.publishedVersio

The cytokinesis-block micronucleus assay on human cryopreserved whole blood and isolated peripheral blood mononuclear cells

Purpose: The cytokinesis-block micronucleus (MN) assay is a widely used technique in human biodosimetry studies, occupational genotoxicity studies and in vitro radiosensitivity testing. Fresh whole blood cultures (WBC) are commonly used for these purposes, but the requirement for immediate processing can be logistically challenging. Therefore, we aimed at establishing two novel protocols for the MN assay on cryopreserved whole blood and fresh or cryopreserved isolated peripheral blood mononuclear cells (PBMCs). Additionally, a thorough evaluation of the reliability of these assays for use in biological dosimetry and radiosensitivity assessment was performed. Materials and methods: The G0 MN assay was performed on fresh and cryopreserved whole blood, freshly isolated and cryopreserved PBMCs from healthy human blood samples. MN yields were scored after irradiation with 220 kV X rays, with doses ranging from 0,5–2 Gy. Additionally, blood samples of 4 patients with a suspected radiosensitive phenotype were analyzed with both protocols. Results: The optimized MN assays on PBMCs and cryopreserved whole blood cultures showed adequate inter-individual and intra-individual variabilities. MN values were significantly lower for fresh PBMCs than for fresh whole blood. Cryopreservation of PBMCs resulted in significant higher MN values compared to fresh PBMCs, while cryopreserved whole blood cultures showed no significant differences in MN yields compared to fresh whole blood cultures. Importantly, after different cryopreservation periods, MN values remained stable for both cryopreserved PBMCs (6 months) and whole blood (1 year). The radiosensitive patients, included in this study, were correctly identified using fresh as well as cryopreserved PBMCs and cryopreserved whole blood. Conclusions: Our new MN assay protocols on fresh PBMCs, cryopreserved PBMCs and cryopreserved whole blood demonstrate to be reliable tools for biodosimetry and radiosensitivity studies

Cryopreserved whole blood and isolated peripheral blood mononuclear cells as alternative sample types for the cytokinesis-block micronucleus assay

Background The cytokinesis-block micronucleus (MN) assay is widely used in basic radiobiological research, environmental biomonitoring studies, biological dosimetry and in vitro radiosensitivity testing. Fresh whole blood cultures are generally used for the MN assay, limiting the application of this assay in studies where immediate processing of fresh samples is logistically challenging. Therefore, we standardized the MN assay on cryopreserved whole blood samples and isolated peripheral blood mononuclear cells (PBMCs). The reliability of both MN assays was thoroughly evaluated for use in radiosensitivity assessment. Materials and methods Blood of healthy donors and radiosensitive patients was collected and the MN assay was performed on fresh whole blood, cryopreserved whole blood and isolated PBMCs. MN yields were scored after irradiation with 220 kV X-rays, with doses ranging from 0.5 - 2 Gy. Results and conclusion Fresh whole blood samples showed the highest MN values, while both cryopreserved PBMCs and cryopreserved whole blood cultures showed similar but slightly lower MN values. Inter-individual and intra-individual variabilities were acceptable for all three sample types. The cryopreservation period of PBMCs or whole blood has no significant impact on MN yields, analyzed up to six months and one year, respectively. In addition, radiosensitive patients could successfully be identified using these alternative sample types. Here, we demonstrate the possibility of using cryopreserved isolated PBMCs or whole blood for the MN assay. Depending on the application, the optimal sample type can be selected. PBMCs are highly advantageous when multiple other assays need to be performed on a single blood sample, while cryopreserved whole blood is favorable when a quick and simple sample storing procedure is required in large-scale multicenter studies. References Sioen S, Cloet K, Vral A, Baeyens A. The Cytokinesis-Block Micronucleus Assay on Human Isolated Fresh and Cryopreserved Peripheral Blood Mononuclear Cells. J Pers Med. 2020 Sep 14;10(3):125. doi: 10.3390/jpm10030125. Beyls E, Baeyens A, Vral A. The cytokinesis-block micronucleus assay for cryopreserved whole blood. Int J Radiat Biol. 2021 Jul 1:1-9. doi: 10.1080/09553002.2021.1941378

Posterior transosseous capsulotendinous repair in total hip arthroplasty : a cadaver study.

BACKGROUND: While recent clinical articles have reported a dramatic reduction in rates of total hip dislocation after posterior transosseous repair, we are not aware of any published biomechanical data to support this finding. The objectives of this study were to investigate the functional anatomy of the posterior transosseous repair and its effect on stability after total hip replacement. METHODS: Six total hip prostheses were implanted into three fresh cadavera. Three different repair situations (no repair, soft-tissue repair, and transosseous fixation) were then consecutively tested on each hip. Values for torque resistance and the angular range of motion at dislocation were recorded. Each repair was tested twice, yielding a total of thirty-six torque values and thirty-six angles of rotation. RESULTS: The transosseous repair was superior with regard to both torsion strength (four times stronger than that after no repair [p = 0.0002] and more than twice as strong as that after soft-tissue repair [p = 0.002]) and the magnitude of the angle of rotation observed prior to dislocation (an increase of 83% in comparison with that after no repair [p = 0.0005] and an increase of 46% in comparison with that after soft-tissue repair [p = 0.004]). CONCLUSIONS: In a cadaver model, posterior transosseous repair provides superior stability of a total hip replacement. Optimal surgical technique with a slightly modified approach allows greater retention of capsule and tendon length and a more anatomical reinsertion of the soft tissues