Ethics in pre-ART genetics: a missed X-linked Menkes disease case.

Assisted reproductive technology (ART) has experienced dramatic progress over the last 30 years, and gamete donation is routine in fertility clinics. Major advances in genetic diagnostics are part of this development due to the ability to analyze multiple genes or whole genomes fast and to an affordable prize. This requires knowledge and capability to evaluate genetic variants correctly in a clinical setting. Here we report a Menkes disease case, born after ART, where genetic screening and variant scoring failed to identify an egg donor as carrier of this fatal X-linked disorder. The gene variant is a deletion of a single base pair leading to a frameshift and premature termination of the protein, predicted to result in no or severely diminished function. The variant would be classified as likely pathogenic (class 4) and should be readily detectable by molecular genetic screening techniques. We wish to highlight this case to prevent future similar cases. IVI Igenomix has developed and embarked on an ambitious screening program to detect and prevent a large number of inherited severe childhood disorders in ART pregnancies. The company has recently achieved ISO 15189 certification with competence to evaluate and deliver timely, accurate, and reliable results. Failure to identify a pathogenic variant in the ATP7A gene leading to birth of two boys with Menkes disease invokes the required procedures to screen and detect disease-causing gene variants. This calls for ethical and legal considerations in ART diagnostics to prevent fatal errors like the present.

Magnetic resonance therapy in the treatment of osteoarthritis: A scoping review.

OBJECTIVES: To primarily assess the existing literature about Magnetic Resonance Therapy (MRT) or Molecular Biophysical Stimulation Therapy (MBST) in the treatment of patients with osteoarthritis (OA). The scoping review question was: What has been reported about MRT or MBST concerning treatment of patients with OA? KEY FINDINGS: The applied treatment program consisted of one hour daily treatment for patients in all the included studies. In terms of duration of treatment, four studies suggested treatment for nine consecutive days, two for five days and one study reported treatment on weekdays for two weeks. Six of the studies investigated the effect of MRT on the knee and one study for finger, ankle, and hip, respectively. Consensus across studies was that MRT had a positive, almost always significant, effect. Six out of the seven studies had subjective outcome measurements such as pain, quality of life and joint function, which were measured through self-reported questionnaires. One study combined ultrasonography with Magnetic Resonance Imaging (MRI) to evaluate structural joint changes. This evaluation was performed by a radiologist. One study used objective measurement of cartilage thickness through a minimal distance algorithm. All tests used MBST-systems. CONCLUSION: This scoping review showed that there seems to be a beneficial effect of MRT in the treatment of patients with OA in relation to improvement in pain, joint function, and quality of life. However, more robust research and further evaluation of MRT are needed. IMPLICATIONS FOR PRACTICE: Treating patients diagnosed with OA with MRT for one hour for five to ten days seemed to improve pain, joint function, quality of life as well as regeneration of cartilage. However, limitations of the included studies in this scoping review, such as a general lack of control groups, low sample sizes, lack of control for confounding factors such as medication, calls for more robust research with stronger study designs.

Stiripentol in the treatment of adults with focal epilepsy- a retrospective analysis.

OBJECTIVES: The aim of the present study was to evaluate the safety and efficacy of the add-on treatment of stiripentol (STP) in adult patients with severely pharmacoresistant focal or multifocal epilepsy. METHODS: Data on adult patients treated with STP from March 2007 to July 2020 and with at least one clinical follow-up (FU) were retrospectively reviewed. Data on tolerability, efficacy and concomitant medication were evaluated at baseline, 6 months (5.5 ± 1.6 months (mean ± SD)) and 12 months (13.1 ± 3.9 months (mean ± SD)). RESULTS: Data of 22 patients (54.5% male, mean age 34.4 ± 17.79 years (mean ± SD), including mean duration of epilepsy 17.6 ± 25.5 years (mean ± SD), median seizure frequency 30 ± 20 (median ± MAD) per month, and 63.6% being severely intellectually disabled, with 3 to 18 previous anti-seizure-drugs (ASD), were collected. After 6 months, 72.7% of the patients were still taking STP, and 31% of the patients were responders, including 13% who were seizure-free. The 12-month retention rate was 54.4 %, the response rate was 36.4% and 13.6% of patients were seizure-free at the 12-month FU. Reasons for discontinuation were increased seizure frequency, hyperammonaemia and encephalopathy. CONCLUSION: STP seems to be a useful option in the treatment of patients with severely pharmacoresistant epilepsy. Prospective trials are necessary to examine the efficacy of STP in adult patients with pharmacoresistant focal epilepsy.

The Mortality After Release from Incarceration Consortium (MARIC): Protocol for a multi-national, individual participant data meta-analysis.

INTRODUCTION: More than 30 million adults are released from incarceration globally each year. Many experience complex physical and mental health problems, and are at markedly increased risk of preventable mortality. Despite this, evidence regarding the global epidemiology of mortality following release from incarceration is insufficient to inform the development of targeted, evidence-based responses. Many previous studies have suffered from inadequate power and poor precision, and even large studies have limited capacity to disaggregate data by specific causes of death, sub-populations or time since release to answer questions of clinical and public health relevance. OBJECTIVES: To comprehensively document the incidence, timing, causes and risk factors for mortality in adults released from prison. METHODS: We created the Mortality After Release from Incarceration Consortium (MARIC), a multi-disciplinary collaboration representing 29 cohorts of adults who have experienced incarceration from 11 countries. Findings across cohorts will be analysed using a two-step, individual participant data meta-analysis methodology. RESULTS: The combined sample includes 1,337,993 individuals (89% male), with 75,795 deaths recorded over 9,191,393 person-years of follow-up. CONCLUSIONS: The consortium represents an important advancement in the field, bringing international attention to this problem. It will provide internationally relevant evidence to guide policymakers and clinicians in reducing preventable deaths in this marginalized population. KEY WORDS: Mortality; incarceration; prison; release; individual participant data meta-analysis; consortium; cohort.

Asymmetry indicates more severe and active disease in Graves' orbitopathy: results from a prospective cross-sectional multicentre study.

PURPOSE: Patients with Graves' orbitopathy can present with asymmetric disease. The aim of this study was to identify clinical characteristics that distinguish asymmetric from unilateral and symmetric Graves' orbitopathy. METHODS: This was a multi-centre study of new referrals to 13 European Group on Graves' Orbitopathy (EUGOGO) tertiary centres. New patients presenting over a 4 month period with a diagnosis of Graves' orbitopathy were included. Patient demographics were collected and a clinical examination was performed based on a previously published protocol. Patients were categorized as having asymmetric, symmetric, and unilateral Graves' orbitopathy. The distribution of clinical characteristics among the three groups was documented. RESULTS: The asymmetric group (n = 83), was older than the symmetric (n = 157) group [mean age 50.9 years (SD 13.9) vs 45.8 (SD 13.5), p = 0.019], had a lower female to male ratio than the symmetric and unilateral (n = 29) groups (1.6 vs 5.0 vs 8.7, p < 0.001), had more active disease than the symmetric and unilateral groups [mean linical Activity Score 3.0 (SD 1.6) vs 1.7 (SD 1.7), p < 0.001 vs 1.3 (SD 1.4), p < 0.001] and significantly more severe disease than the symmetric and unilateral groups, as measured by the Total Eye Score [mean 8.8 (SD 6.6) vs 5.3 (SD 4.4), p < 0.001, vs 2.7 (SD 2.1), p < 0.001]. CONCLUSION: Older age, lower female to male ratio, more severe, and more active disease cluster around asymmetric Graves' orbitopathy. Asymmetry appears to be a marker of more severe and more active disease than other presentations. This simple clinical parameter present at first presentation to tertiary centres may be valuable to clinicians who manage such patients.

Prior placental bed disorders and later dementia: a retrospective Swedish register-based cohort study.

OBJECTIVE: To investigate the association between a history of placental bed disorders and later dementia. DESIGN: Retrospective population-based cohort study. SETTING: Sweden. SAMPLE: All women giving birth in Sweden between 1973 and 1993 (1 128 709). METHODS: Women with and without placental bed disorders (hypertensive disorders of pregnancy including pre-eclampsia, fetal growth restriction, spontaneous preterm labour and birth, preterm premature rupture of membranes, abruptio placenta, late miscarriages) and other pregnancy complications were identified by means of the Swedish Medical Birth Register. International classification of disease was used. Data were linked to other National Registers. Participants were followed up until 2013. The Cox proportional hazards model was used to calculate hazard ratios for women with and without pregnancy complications and were adjusted for possible confounders. MAIN OUTCOME MEASURES: Diagnosis of vascular dementia and non-vascular dementia. RESULTS: Adjusted for cardiovascular disease and socio-demographic factors, an increased risk of vascular dementia was shown in women with previous pregnancy-induced hypertension (Hazard ratio [HR] 1.88, 95% CI 1.32-2.69), pre-eclampsia (HR 1.63, 95% CI 1.23-2.16), spontaneous preterm labour and birth (HR 1.65, 95% CI 1.12-2.42) or preterm premature rupture of membranes (HR 1.60, 95% CI 1.08-2.37). No statistically significant increased risk was seen for other pregnancy complications or non-vascular dementia even though many of the point estimates indicated increased risks. CONCLUSIONS: Women with placental bed disorders have a higher risk for vascular disease. Mechanisms behind the abnormal placentation remain elusive, although maternal constitutional factors, abnormal implantation as well as impaired angiogenesis have been suggested. TWEETABLE ABSTRACT: Placental bed syndromes associated with vascular dementia even after adjusting for cardiovascular disease.

Traumatic experiences, ICD-11 PTSD, ICD-11 complex PTSD, and the overlap with ICD-10 diagnoses.

OBJECTIVES: This study investigated the frequency of traumatic experiences, prevalence rates of ICD-11 post-traumatic stress disorder (PTSD) and complex PTSD (CPTSD), and overlap with ICD-10 classified disorders in outpatient psychiatry. METHOD: Overall, 165 Danish psychiatric outpatients answered the International Trauma Questionnaire, the Life Event Checklist, and the World Health Organization Well-being Index. ICD-10 diagnoses were extracted from the hospital record. Chi-square analysis, t-tests, and conditional probability analysis were used for statistical analysis. RESULTS: Nearly, all patients (94%) had experienced at least one traumatic event. CPTSD (36%) was more common than PTSD (8%) and had considerable overlap with ICD-10 affective, anxiety, PTSD, personality, adjustment and stress-reaction disorders, and behavioural and emotional disorders with onset usually occurring in childhood and adolescence. ICD-11 PTSD overlapped with ICD-10 anxiety, PTSD, adjustment and stress-reaction disorders, and behavioural and emotional disorders with onset usually occurring in childhood and adolescence. A subgroup of patients with ICD-10 PTSD (23%) did not meet criteria for ICD-11 PTSD or CPTSD. CONCLUSION: Traumatic experiences are common. ICD-11 CPTSD is a highly prevalent disorder in psychiatric outpatients. One quarter with ICD-10 PTSD did not meet criteria for either ICD-11 PTSD or CPTSD. PTSD and CPTSD had considerable overlap with ICD-10 disorders.

Cryptic lineage differentiation among Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the northwest Indian Ocean.

Phylogeography can provide insight into the potential for speciation and identify geographic regions and evolutionary processes associated with species richness and evolutionary endemism. In the marine environment, highly mobile species sometimes show structured patterns of diversity, but the processes isolating populations and promoting differentiation are often unclear. The Delphinidae (oceanic dolphins) are a striking case in point and, in particular, bottlenose dolphins (Tursiops spp.). Understanding the radiation of species in this genus is likely to provide broader inference about the processes that determine patterns of biogeography and speciation, because both fine-scale structure over a range of kilometers and relative panmixia over an oceanic range are known for Tursiops populations. In our study, novel Tursiops spp. sequences from the northwest Indian Ocean (including mitogenomes and two nuDNA loci) are included in a worldwide Tursiops spp. phylogeographic analysis. We discover a new 'aduncus' type lineage in the Arabian Sea (off India, Pakistan and Oman) that diverged from the Australasian lineage ∼261 Ka. Effective management of coastal dolphins in the region will need to consider this new lineage as an evolutionarily significant unit. We propose that the establishment of this lineage could have been in response to climate change during the Pleistocene and show data supporting hypotheses for multiple divergence events, including vicariance across the Indo-Pacific barrier and in the northwest Indian Ocean. These data provide valuable transferable inference on the potential mechanisms for population and species differentiation across this geographic range.

A 37-year-old Menkes disease patient-Residual ATP7A activity and early copper administration as key factors in beneficial treatment.

Menkes disease (MD) is a lethal disorder characterized by severe neurological symptoms and connective tissue abnormalities; and results from malfunctioning of cuproenzymes, which cannot receive copper due to a defective intracellular copper transporting protein, ATP7A. Early parenteral copper-histidine supplementation may modify disease progression substantially but beneficial effects of long-term treatment have been recorded in only a few patients. Here we report on the eldest surviving MD patient (37 years) receiving early-onset and long-term copper treatment. He has few neurological symptoms without connective tissue disturbances; and a missense ATP7A variant, p.(Pro852Leu), which results in impaired protein trafficking while the copper transport function is spared. These findings suggest that some cuproenzymes maintain their function when sufficient copper is provided to the cells; and underline the importance of early initiated copper treatment, efficiency of which is likely to be dependent on the mutant ATP7A function.

A novel holistic framework for genetic-based captive-breeding and reintroduction programs.

Research in reintroduction biology has provided a greater understanding of the often limited success of species reintroductions and highlighted the need for scientifically rigorous approaches in reintroduction programs. We examined the recent genetic-based captive-breeding and reintroduction literature to showcase the underuse of the genetic data gathered. We devised a framework that takes full advantage of the genetic data through assessment of the genetic makeup of populations before (past component of the framework), during (present component), and after (future component) captive-breeding and reintroduction events to understand their conservation potential and maximize their success. We empirically applied our framework to two small fishes: Yarra pygmy perch (Nannoperca obscura) and southern pygmy perch (Nannoperca australis). Each of these species has a locally adapted and geographically isolated lineage that is endemic to the highly threatened lower Murray-Darling Basin in Australia. These two populations were rescued during Australia's recent decade-long Millennium Drought, when their persistence became entirely dependent on captive-breeding and subsequent reintroduction efforts. Using historical demographic analyses, we found differences and similarities between the species in the genetic impacts of past natural and anthropogenic events that occurred in situ, such as European settlement (past component). Subsequently, successful maintenance of genetic diversity in captivity-despite skewed brooder contribution to offspring-was achieved through carefully managed genetic-based breeding (present component). Finally, genetic monitoring revealed the survival and recruitment of released captive-bred offspring in the wild (future component). Our holistic framework often requires no additional data collection to that typically gathered in genetic-based breeding programs, is applicable to a wide range of species, advances the genetic considerations of reintroduction programs, and is expected to improve with the use of next-generation sequencing technology.

Mutational and phenotypical spectrum of phenylalanine hydroxylase deficiency in Denmark.

We describe the genotypes of the complete cohort, from 1967 to 2014, of phenylketonuria (PKU) patients in Denmark, in total 376 patients. A total of 752 independent alleles were investigated. Mutations were identified on 744 PKU alleles (98.9%). In total, 82 different mutations were present in the cohort. The most frequent mutation c.1315+1G>A (IVS12+1G>A) was found on 25.80% of the 744 alleles. Other very frequent mutations were c.1222C>T (p.R408W) (16.93%) and c.1241A>G (p.Y414C) (11.15%). Among the identified mutations, five mutations; c.532G>A (p.E178K), c.730C>T (p.P244S), c.925G>A (p.A309T), c.1228T>A (p.F410I), and c.1199+4A>G (IVS11+4A>G) have not been reported previously. The metabolic phenotypes of PKU are classified into four categories; 'classical PKU', 'moderate PKU', 'mild PKU' and 'mild hyperphenylalaninemia'. In this study, we assigned the phenotypic outcome of three of the five novel mutations and furthermore six not previously classified mutations to one of the four PKU categories.

Psychiatric illness in women requesting caesarean section.

OBJECTIVE: To compare psychiatric in- and outpatient care during the 5 years before first delivery in primiparae delivered by caesarean section on maternal request with all other primiparae women who had given birth during the same time period. DESIGN: Prospective, population-based register study. SETTING: Sweden. SAMPLE: Women giving birth for the first time between 2002 and 2004 (n = 64 834). METHODS: Women giving birth by caesarean section on maternal request (n = 1009) were compared with all other women giving birth (n = 63 825). The exposure of interest was any psychiatric diagnosis according to the International Statistical Classification of Diseases and Related Health Problems (ninth revision, ICD-9, 290-319; tenth revision, ICD-10, F00-F99) in The Swedish national patient register during the 5 years before first delivery. MAIN OUTCOME MEASURES: Psychiatric diagnoses and delivery data. RESULTS: The burden of psychiatric illnesses was significantly higher in women giving birth by caesarean section on maternal request (10 versus 3.5%, P < 0.001). The most common diagnoses were 'Neurotic disorders, stress-related disorders and somatoform disorders' (5.9%, aOR 3.1, 95% CI 1.1-2.9), and 'Mood disorders' (3.4%, aOR 2.4, 95% CI 1.7-3.6). The adjusted odds ratio for caesarean section on maternal request was 2.5 (95% CI 2.0-3.2) for any psychiatric disorder. Women giving birth by caesarean section on maternal request were older, used tobacco more often, had a lower educational level, higher body mass index, were more often married, unemployed, and their parents were more often born outside of Scandinavia (P < 0.05). CONCLUSIONS: Women giving birth by caesarean section on maternal request more often have a severe psychiatric disease burden. This finding points to the need for psychological support for these women as well as the need to screen and treat psychiatric illness in pregnant women.

Reproduction and mode of delivery in women with vaginismus or localised provoked vestibulodynia: a Swedish register-based study.

OBJECTIVE: To compare sociodemographics, parity and mode of delivery between women diagnosed with vaginismus or localised provoked vestibulodynia (LPV) to women without a diagnosis before first pregnancy. DESIGN: Retrospective, population-based register study. SETTING: Sweden. SAMPLE: All women born in Sweden 1973-83 who gave birth for the first time or remained nulliparous during the years 2001-09. METHODS: Nationally linked registries were used to identify the study population. Women diagnosed with vaginismus or LPV were compared to all other women. Odds ratios for parity and mode of delivery were calculated using multinominal regression analysis and logistic regression. MAIN OUTCOME MEASURES: Parity and mode of delivery. RESULTS: Women with vaginismus/LPV were more likely to be unmarried (P = 0.001), unemployed (P = 0.012), have a higher educational level (P < 0.001), a lower body mass index (P < 0.001) and use nicotine during pregnancy (P = 0.008). They were less likely to give birth (adjusted odds ratio [OR] 0.61, 95% confidence interval [95% CI] 0.56-0.67). Women with vaginismus/LPV more often delivered by caesarean section (P < 0.001) especially for maternal request (adjusted OR 3.48, 95% CI 2.45-4.39). In women having vaginal delivery, those with vaginismus/LPV were more likely to suffer a perineal laceration (adjusted OR 1.87, 95% CI 1.56-2.25). CONCLUSIONS: Women with vaginismus/LPV are less likely to give birth and those that do are more likely to deliver by caesarean section and have a caesarean section based upon maternal request. Those women delivering vaginally are more likely to suffer perineal laceration. These findings point to the importance of not only addressing sexual function in women with vaginismus/LPV but reproductive function as well.

Separate norovirus outbreaks linked to one source of imported frozen raspberries by molecular analysis, Denmark, 2010-2011.

Norovirus outbreaks occur frequently in Denmark and it can be difficult to establish whether apparently independent outbreaks have the same origin. Here we report on six outbreaks linked to frozen raspberries, investigated separately over a period of 3 months. Norovirus from stools were sequence-typed; including extended sequencing of 1138 bp encompassing the hypervariable P2 region of the capsid gene. Norovirus was detected in 27 stool samples. Genotyping showed genotype GI.Pb_GI.6 (polymerase/capsid) with 100% identical sequences. Samples from five outbreaks were furthermore identical over the variable capsid P2 region. In one outbreak at a hospital canteen, frozen raspberries was associated with illness by cohort investigation (relative risk 6·1, 95% confidence interval 3·2-11). Bags of raspberries suspected to be the source were positive for genogroup I and II noroviruses, one typable virus was genotype GI.6 (capsid). These molecular investigations showed that the apparently independent outbreaks were the result of one contamination event of frozen raspberries. The contaminated raspberries originated from a single producer in Serbia and were originally not considered to belong to the same batch. The outbreaks led to consultations and mutual visits between producers, investigators and authorities. Further, Danish legislation was changed to make heat-treatment of frozen raspberries compulsory in professional catering establishments.

Expression patterns of DLK1 and INSL3 identify stages of Leydig cell differentiation during normal development and in testicular pathologies, including testicular cancer and Klinefelter syndrome.

STUDY QUESTION: What is the differentiation stage of human testicular interstitial cells, in particular Leydig cells (LC), within micronodules found in patients with infertility, testicular cancer and Klinefelter syndrome? SUMMARY ANSWER: The Leydig- and peritubular-cell populations in testes with dysgenesis contain an increased proportion of undifferentiated cells when compared with control samples, as demonstrated by increased delta-like homolog 1 (DLK1) and decreased insulin-like peptide 3 (INSL3) expression. WHAT IS KNOWN ALREADY: Normal LC function is essential for male development and reproduction. Signs of LC failure, including LC micronodules, are often observed in patients with reproductive disorders. STUDY DESIGN, SIZE, PARTICIPANTS: In this retrospective study, a panel of markers and factors linked to the differentiation of LCs was investigated in 33 fetal and prepubertal human specimens and in 58 adult testis samples from patients with testicular germ cell tumours, including precursor carcinoma in situ (CIS), infertility or Klinefelter syndrome. PARTICIPANTS/MATERIALS, SETTING, METHODS: The expression patterns of DLK1, INSL3, chicken ovalbumin upstream promoter transcription factor 2 (COUP-TFII), cytochrome P450, family 11, subfamily A, polypeptide 1 (CYP11A1) and smooth muscle actin (SMA) were investigated by immunohistochemistry and quantitative RT-PCR. The percentage of positive LCs was estimated and correlated to total LC numbers and serum levels of reproductive hormones. MAIN RESULTS AND THE ROLE OF CHANCE: DLK1, INSL3 and COUP-TFII expression changed during normal development and was linked to different stages of LC differentiation: DLK1 was expressed in all fetal LCs, but only in spindle-shaped progenitor cells and in a small subset of polygonal LCs in the normal adult testis; INSL3 was expressed in a subset of fetal LCs, but in the majority of adult LCs; and COUP-TFII was expressed in peritubular and mesenchymal stroma cells at all ages, in fetal LCs early in gestation and in a subset of adult LCs. CYP11A1 was expressed in the majority of LCs regardless of age and pathology and was the best general LC marker examined here. SMA was weakly expressed in peritubular cells in the fetal and infantile testis, but strongly expressed in the adult testis. In pathological testes, the numbers of DLK1-positive interstitial cells were increased. The proportion of DLK1-positive LCs correlated with total LC numbers (R = 0.53; P < 0.001) and was higher in testis with enlargement of the peritubular layers (P < 0.01), which was also highly associated with DLK1 expression in the peritubular compartment (P < 0.001). INSL3 expression was absent in some, but not all LC micronodules, and in the majority of LCs, it was mutually exclusive of DLK1. LIMITATIONS, REASONS FOR CAUTION: The number of samples was relatively small and no true normal adult controls were available. True stereology was not used for LC counting, instead LCs were counted in three fields of 0.5 µm(2) surface for each sample. WIDER IMPLICATIONS OF THE FINDINGS: The population of LCs, especially those clustered in large nodules, are heterogeneous and comprise cells at different stages of differentiation. The study demonstrated that the differentiation and function of LCs, and possibly also peritubular cells, are impaired in adult men with testicular pathologies including testis cancer and Klinefelter syndrome. STUDY FUNDING/COMPETING INTERESTS: This work was funded by Rigshospitalet's research funds, the Danish Cancer Society and Kirsten and Freddy Johansen's foundation. The authors have no conflicts of interest.

Hemolytic properties of synthetic nano- and porous silica particles: the effect of surface properties and the protection by the plasma corona.

Novel silica materials incorporating nanotechnology are promising materials for biomedical applications, but their novel properties may also bring unforeseen behavior in biological systems. Micro-size silica is well documented to induce hemolysis, but little is known about the hemolytic activities of nanostructured silica materials. In this study, the hemolytic properties of synthetic amorphous silica nanoparticles with primary sizes of 7-14 nm (hydrophilic vs. hydrophobic), 5-15 nm, 20 nm and 50 nm, and model meso/macroporous silica particles with pore diameters of 40 nm and 170 nm are investigated. A crystalline silica sample (0.5-10 µm) is included for benchmarking purposes. Special emphasis is given to investigations of how the temperature and solution complexity (solvent, plasma), as well as the physicochemical properties (such as size, surface charge, hydrophobicity and other surface properties), link to the hemolytic activities of these particles. Results suggests the potential importance of small size and large external surface area, as well as surface charge/structure, in the hemolysis of silica particles. Furthermore, a significant correlation is observed between the hemolytic profile of red blood cells and the cytotoxicity profile of human promyelocytic leukemia cells (HL-60) induced by nano- and porous silica particles, suggesting a potential universal mechanism of action. Importantly, the results generated suggest that the protective effect of plasma towards silica nanoparticle-induced hemolysis as well as cytotoxicity is primarily due to the protein/lipid layer shielding the silica particle surface. These results will assist the rational design of hemocompatible silica particles for biomedical applications.

DNA damage induced by micro- and nanoparticles--interaction with FPG influences the detection of DNA oxidation in the comet assay.

Reliable methods for evaluation of toxicity from particles, such as manufactured nanoparticles, are needed. One promising tool is the comet assay, often used to measure DNA breaks (strand breaks and alkali-labile sites) as well as oxidatively damaged DNA, the latter by addition of specific DNA repair enzymes such as formamidopyrimidine DNA glycosylase (FPG). The aim of this study was to investigate the use of the comet assay for analysis of DNA oxidation by a range of micro- and nanoparticles in the lung cell lines A549 and BEAS-2B and to test the hypothesis that nanoparticles present in the cells during the assay performance may interact with FPG. This was done by investigating the ability of micro- and nanoparticles (stainless steel, subway particles, MnO(2), Ag, CeO(2), Co(3)O(4), Fe(3)O(4), NiO and SiO(2)) to induce DNA breaks, oxidatively damaged DNA (FPG sites, dominantly 8-oxoguanine), intracellular production of reactive oxygen species (ROS) and non-cellular oxidation of the DNA base guanine, as well as by studying interactions of the particles and their released ions with FPG. Several particles caused DNA breaks, but low levels of FPG sites. The ability of FPG to detect DNA oxidation induced by a photosensitiser was however shown. An oxidative capacity of the particles was indicated by increased levels of intracellular ROS, and especially Ag and subway particles caused non-cellular oxidation of guanine. Incubation of FPG with the particles led to less FPG activity, particularly with nanoparticles of Ag but also with CeO(2), Co(3)O(4) and SiO(2). Further investigations of these particles revealed that for Ag, the decreased activity was mainly due to released Ag ions, whereas for CeO(2) and Co(3)O(4), FPG interactions were due to the particles. We conclude that measurement of oxidatively damaged DNA in cells exposed to nanoparticles may be underestimated in the comet assay due to interactions with FPG.