Herpes Simplex Virus 1 and 2 Infections during Differentiation of Human Cortical Neurons

Herpes simplex virus 1 (HSV-1) and 2 (HSV-2) can infect the central nervous system (CNS) with dire consequences; in children and adults, HSV-1 may cause focal encephalitis, while HSV-2 causes meningitis. In neonates, both viruses can cause severe, disseminated CNS infections with high mortality rates. Here, we differentiated human induced pluripotent stem cells (iPSCs) towards cortical neurons for infection with clinical CNS strains of HSV-1 or HSV-2. Progenies from both viruses were produced at equal quantities in iPSCs, neuroprogenitors and cortical neurons. HSV-1 and HSV-2 decreased viability of neuroprogenitors by 36.0% and 57.6% (p < 0.0001), respectively, 48 h post-infection, while cortical neurons were resilient to infection by both viruses. However, in these functional neurons, both HSV-1 and HSV-2 decreased gene expression of two markers of synaptic activity, CAMK2B and ARC, and affected synaptic activity negatively in multielectrode array experiments. However, unaltered secretion levels of the neurodegeneration markers tau and NfL suggested intact axonal integrity. Viral replication of both viruses was found after six days, coinciding with 6-fold and 22-fold increase in gene expression of cellular RNA polymerase II by HSV-1 and HSV-2, respectively. Our results suggest a resilience of human cortical neurons relative to the replication of HSV-1 and HSV-2.

Control computerized tomography in neoadjuvant chemotherapy for muscle invasive urinary bladder cancer, has no value for treatment decisions and low correlation with nodal status

BACKGROUND

Control computerized tomography (cCT) is routinely used in many cystectomy centres before the final treatment cycle in patients with muscle-invasive urinary bladder cancer (MIBC) undergoing neoadjuvant chemotherapy (NAC). This is for evaluating response or nonresponse to NAC treatment. In a real-world retrospective cohort, we intended to evaluate the frequency of changed individual treatment strategies following cCT and to investigate any discrepancies between cCT-results on nodal staging and final pN-stages.

METHODS

We performed a retrospective data-based, multicenter study of 242 MIBC-patients, staged cT2N0M0-cT4aN0M0, having undergone NAC and radical cystectomy (RC) between 2008 and 2019 at four Swedish cystectomy centres. Statistical analysis was performed using IBM SPSS statistics 26.

RESULTS

Overall, 139/242 patients were examined with cCT. Six patients were staged as progressive at cCT and 5/139 (3.6%) underwent a change of previously planned treatment strategy. 2/6 patients with suspected progression (33%) did not change strategy and underwent all preplanned NAC-cycles plus RC. Only 1/6 patients assigned as progressive at the cCT, showed progression in the postoperative pathology specimen. In total 133/139 patients were considered being without progress on cCT, yet 28/133 (21%) presented with nodal progression at postoperative pathology examinations. Only 1/29 patients with histopathologically verified nodal dissemination were detected with cCT, thus 28/29 (96.6%) with pN + were undetected. The sensitivity for cCT to predict pTNM was 17% CI [0%-64%] and the specificity was 78% CI [71%-86%].

CONCLUSIONS

CCT prior to the final treatment cycle of NAC in MIBC, leads to a low percentage of treatment strategy changes and cCT cannot accurately predict pN-status.

Ambivalence among staff regarding ageing with intellectual disabilities: Experiences and reflections

This study explores the experiences and reflections of staff in intellectual disability (ID) services concerning ageing with ID. Qualitative interviews were conducted with 24 staff members in group homes and daily activity centres. The findings showed that the staff were uncertain about the signs of ageing in people with intellectual disabilities; they compared the life conditions of these people with conditions in older people without intellectual disabilities. Their emphasis on an active lifestyle was very strong. The staff members also mentioned uncertainty about how to facilitate assistive devices and whether 'ageing in place' was the best solution. The overall theme was manifested as ambivalence where notions of older people with intellectual disabilities seemed incompatible with notions of old age in general and could be explained by the theoretical concept of age coding. The findings of this study indicate the need to provide education about ageing to staff working in ID services.

Association of incident fragility fractures in patients hospitalised due to unexplained syncope and orthostatic hypotension

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): The study was funded by The Swedish Heart-Lung Foundation, The Greta and Johan Kock Foundation, and an Agreement for Medical Education and Research (ALF) grant by Swedish Research Council funding for clinical research in medicine.

Background

Fragility fractures are caused by low-energy insults such as falls from standing height or less and pose a growing health challenge as their incidence rises with increasing age. Impaired orthostatic blood pressure response and a number of cardiovascular biomarkers have been previously identified as risk factors for fractures. It is likely that severe episodes of syncope and orthostatic hypotension increase the risk of subsequent fragility fractures, however this relationship has not been thoroughly examined.

Purpose

To investigate the relationship of hospital admissions due to unexplained syncope and OH with incident fragility fractures in a middle-aged population.

Methods

We analysed a large population-based prospective cohort of 30,446 middle-aged individuals (age, 57.5 ± 7.6; men, 39.8%). We included patients hospitalised due to unexplained syncope and OH. Cox regression analysis adjusted for age, sex, prevalent fractures, body mass index (BMI) were applied to assess the impact of unexplained syncope/OH hospitalisations on subsequent incident fragility fractures. Prevalent fractures occurring before syncope/OH hospitalisation were excluded (n = 39) as well as cases with no follow-up time after the event of syncope/OH (n= 8).

Results

The mean follow-up from baseline to first incident fracture or end of follow-up was 17.8 + 6.5 years, and 8201 (27%) suffered incident fracture. The mean age of patients with unexplained syncope (n = 493) and OH patients (n = 406) at baseline was 61.5 ± 7.1 years (50.1%, male) and 62.6 ± 6.6 years (49.8% male), respectively. The mean time between baseline and first admission for syncope and OH was 12.3 ± 4.5 years, and the mean age at first hospitalisation was 74.4 ± 7.6 years. In the multivariable-adjusted Cox regression, the risk of subsequent incident fractures was increased among patients hospitalised due to unexplained syncope (HR: 1.20; 95% CI 1.03–1.40; p &lt; 0.02) and OH (HR: 1.40; 95% CI 1.20–1.64; p &lt; 0.001), respectively (Kaplan-Meier curves; Figure 1).

Conclusions

Patients hospitalised due to unexplained syncope and OH demonstrate increased risk of subsequent fragility fractures. We suggest that patients who are hospitalised for unexplained syncope and OH should be clinically assessed for true syncope aetiology, systematically treated against fall risk, and evaluated for additional risk factors for fragility fractures. Abstract Figure 1. Kaplan-Meier curves

Effect of aging on cerebral tissue oxygenation in relation to reflex syncope

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Swedish Heart and Lung Foundation, The Swedish Heart and Lung Association, ALF funds, Skåne University Hospital Funds, The Crafoord Foundation.

Background

There is an increased susceptibility to syncope with aging attributed to age-related physiological impairments. Cerebral oximetry non-invasively measures cerebral tissue oxygenation (SctO2) and has been shown to be valuable in syncope evaluation. SctO2 has been found to decrease with aging but it is unknown whether the decrease in SctO2 is related to increased susceptibility to syncope during orthostatic provocation. By measuring SctO2 during head up tilt test (HUT) we can study age-related differences in SctO2 and their impact on developing reflex syncope.

Purpose

To investigate the effect of age on the cerebral tissue oxygenation threshold for syncope and presyncope among patients with vasovagal syncope.

Methods

Non-invasive haemodynamic monitoring and near-infrared spectroscopy (NIRS) were applied during head-up tilt (HUT) in 139 vasovagal syncope patients (mean [SD] 45[17] years, 60% female), and 82 control patients with a normal response to HUT (45[18] years, 61% female). Group differences in SctO2 and systolic blood pressure (SBP) during HUT in supine position, after 3 and 10 min of HUT, 30 seconds prior to syncope ("presyncopal phase") and during syncope in different age groups (&lt;30, 30-60 and  &gt;60 years) were compared using one-way ANOVA and Tukey"s multiple comparison test. Associations between age and SctO2 were studied using linear regression models adjusted for sex and concurrent SBP.

Results

Lower SctO2 in supine position was associated with increasing age among controls (B=-0.085, p = 0.010) but not among VVS patients (B=-0.036, p = 0.114). No age-related differences in SctO2 were found after 3 and 10 minutes of HUT and during syncope.  Mean SctO2 (%) during the presyncopal phase decreased over the advancing age groups (&lt;30: 66.9 ± 6.2, 30-60: 64.5 ± 6.1, &gt;60: 62.2 ± 5.8; p = 0.009 for inter-group comparison). In contrast, mean SBP during the presyncopal phase did not differ by age groups (&lt;30: 85.6 ± 21.8, 30-60: 77.6 ± 19.7, &gt;60: 77.6 ± 20.8 mmHg, p = 0.133). Age was associated with lower SctO2 during the presyncopal phase after adjusting for sex and SBP (B = 0.096, p = 0.001).

Conclusion

Older VVS patients have lower cerebral tissue oxygenation in the presyncopal phase compared with younger patients independently of systolic blood pressure. These results suggest either that with imminent reflex syncope cerebral tissue oxygenation diminishes more with advancing age or that cerebral deoxygenation is better tolerated by older reflex syncope patients. Abstract Figure.

Role of Aurora B and Haspin kinases in the metaphase Topoisomerase II checkpoint

DNA Topoisomerase II (TopoII) uses ATP hydrolysis to decatenate chromosomes so that sister chromatids can faithfully segregate in mitosis. When the TopoII enzyme cycle stalls due to failed ATP hydrolysis, the onset of anaphase is delayed, presumably to allow extra time for decatenation to be completed. Recent evidence revealed that, unlike the spindle assembly checkpoint, this TopoII checkpoint response requires Aurora B and Haspin kinases and is triggered by SUMOylation of the C-terminal domain of TopoII.

Gamma-radiation induced synthesis of freestanding nickel nanoparticles

A versatile method to produce metallic nickel nanoparticles is demonstrated. Metallic Ni nanoparticles have been synthesized from aqueous solution of NiCl₂ using γ-radiation induced reduction. To prevent Ni re-oxidation, post-irradiation treatment was elaborated. Structural and compositional analyses were executed using X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. These studies reveal that the synthesized material consists of fcc Ni particles having size of 3.47 ± 0.71 nm. The nanoparticles have a tendency to agglomerate to the larger clusters. The latter are partially oxidized to form thin amorphous/poor-crystalline Ni(OH)₂/NiO layers at the surface. Magnetization measurements demonstrate that the nanomaterial exhibit ferromagnetic-like behaviour with magnetization 30% lower than that in bulk Ni. The large active surface area (ECSA, 39.2 m² g^-1) and good electrochemical reversibility, confirmed by the electrochemical studies, make the synthesized material a potential candidate as an active component for energy storage devices.

The changed relations between the construction industry and occupational health services

BACKGROUND: From the 1960s until the beginning of the 1990s, the construction industry in Sweden received support for health and safety issues from Bygghälsan, an Occupational Health Service (OHS) that targeted the construction industry. In the 1990s, a reorganization of the OHS changed the relations between the actors involved. OBJECTIVES: This study explores these changed relations between the construction industry and the “old” industry-specific Bygghälsan versus the relations with “new” external OHS. METHODS: Semi-structured interviews were conducted with 22 interviewees from the construction industry and individuals involved in OHS which were transcribed and analyzed. RESULTS: The results suggest that OHS have changed towards a more general character instead of tailor-made services which has had a negative effect on the relations. Further, Bygghälsan was perceived as being a part of the construction industry while contemporary OHS providers were perceived as outsiders which further complicates building trustful relations. CONCLUSIONS: The relation between the construction industry and Bygghälsan was perceived as better compared to the relations with the new companies providing external OHS. The main barrier to building better relations is the perception that contemporary OHS do not have the same knowledge about the construction industry as Bygghälsan.

Downregulation of growth hormone in postural orthostatic tachycardia syndrome: insights from the SYSTEMA cohort

Background

Postural orthostatic tachycardia syndrome (POTS) is a variant of cardiovascular autonomic disorder occurring predominantly in young women. POTS is characterized by an excessive heart rate increase when assuming upright posture accompanied by symptoms of orthostatic intolerance. The pathophysiology of POTS has not been fully established and is believed to be multifactorial.

Purpose

We aimed to investigate the alterations in circulating growth hormone level in POTS.

Methods

We conducted an age-matched case-control study enrolling 42 patients with POTS (age 31±9 years; 36 women) verified by positive head-up tilt testing and cardiovascular autonomic tests, and 46 controls (32±9 years; 35 women) with negative active standing test and no history of syncope, orthostatic intolerance and endocrine disease. We measured plasma levels of growth hormone using a high-sensitivity chemiluminescence immunoassay in relation to presence of POTS diagnosis. All study participants completed the validated Orthostatic Hypotension Questionnaire (OHQ), consisting of two components: the symptoms assessment scale (OHSA) and daily activity scale (OHDAS) to evaluate the burden of symptoms. We applied standard statistical tests for group differences. Growth hormone values were log-transformed and standardized before the group comparison.

Results

POTS patients had significantly lower plasma levels of growth hormone (ng/mL) (median=0.53, IQR, 0.10–2.83 vs. median=2.33, IQR, 0.26–7.2, p=0.04) than controls. Levels of growth hormone were reversely related to OHDAS (p=0.049) among POTS patients. Supine heart rate was significantly higher in POTS patients (69.0±11.1 beats/min vs. 63.3±10.8 beats/min, p=0.02), as well as diastolic blood pressure (72.9±9.1 mmHg vs. 69.0±8.5 mmHg, p=0.04). We observed no significant difference in supine systolic blood pressure (116.6±13.3 mmHg vs. 115.2±10.0 mmHg, p=0.60). POTS patients had a significantly higher composite OHQ score than controls (60.0±18.6 vs. 4.2±7.5, p&lt;0.001), as well as OHSA (36.2±10.0 vs. 3.6±6.4, p&lt;0.001) and OHDAS (23.8±9.7 vs. 0.6±1.3, p&lt;0.001).

Conclusion(s)

Our study shows that patients with POTS have significantly reduced plasma levels of circulating growth hormone. Lower growth hormone levels among POTS patients are associated with increased impairment of daily life activities. Further studies are necessary to confirm our findings in the independent populations and explain the mechanisms behind this alteration.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Crafoord Foundation, Swedish Heart and Lung Foundation

Livestock owners' worry and fear of tick-borne diseases

Background

Recent global changes have led to an increase in distribution of ticks towards higher elevation and latitude in Europe and livestock are at increasing risk of contracting tick-borne diseases, but psychological aspects of how this affects human well-being are rarely assessed. Departing from the theory on emotional appraisal coming from psychology, this study investigates which factors that modulate worry and fear associated with the presence of ticks among livestock owners of sheep and/or cattle.

Methods

Survey data from 775 livestock owners in Norway were analysed by hierarchical multiple regression analysis with an index of fear of tick-borne diseases among livestock as the outcome variable.

Results

Twenty-nine per cent of the livestock owners reported worry and fear of tick-borne diseases among their livestock. The model explained 35% of the variance in worry and fear. There was a weak association between estimated incidences of tick-borne diseases in livestock and livestock owners’ worry and fear. Whereas previous personal experience of ticks and tick-borne diseases in livestock, and the livestock owners’ appraisals of the situation were more strongly associated with relatively stronger feelings of worry and fear.

Conclusions

Livestock owners’ worry and fear of tick-borne diseases in livestock can partly be understood as their appraisals of perceived personal relevance of the presence of ticks, its potential negative implications for their daily life at large, and what potential they have to cope by different strategies to adapt or adjust to the situation.

Staff experiences of a new tool for comprehensive geriatric assessment in primary care (PASTEL): a focus group study

Objective: Comprehensive geriatric assessment (CGA) is recommended for the management of frailty. Little is known about professionals' experiences of CGA; therefore we wanted to investigate the experiences of staff in primary care using a new CGA tool: the Primary care Assessment Tool for Elderly (PASTEL).Design: Focus group interviews. Manifest qualitative content analysis.Setting: Nine primary health care centres in Sweden that participated in a CGA intervention. These centres represent urban as well as rural areas.Subjects: Nine nurses, five GPs and one pharmacist were divided into three focus groups.Main outcome measures: Participants' experiences of conducting CGA with PASTEL.Results: The analysis resulted in four main categories. A valuable tool for selected patients: The participants considered the assessment tool to be feasible and valuable. They stated that having enough time for the assessment interview was essential but views about the ideal patient for assessment were divided. Creating conditions for dialogue: The process of adapting the assessment to the individual and create conditions for dialogue was recognised as important. Managing in-depth conversations: In-depth conversations turned out to be an important component of the assessment. Patients were eager to share their stories, but talking about the future or the end of life was demanding. The winding road of actions and teamwork: PASTEL was regarded as a good preparation tool for care planning and a means of support for identifying appropriate actions to manage frailty but there were challenges to implement these actions and to obtain good teamwork.Conclusion: The participants reported that PASTEL, a tool for CGA, gave a holistic picture of the older person and was helpful in care planning.Key pointsTo manage frailty using comprehensive geriatric assessment (CGA) in primary care, there is a need for tools that are efficient, user-friendly and which support patient involvement and teamwork•This study found that the Primary care Assessment tool for Elderly (PASTEL) is regarded as both valuable and feasible by primary care professionals•Use of carefully selected items in the tool and allowing enough time for dialogue may enhance patient-centeredness•The PASTEL tool supports the process of identifying actions to manage frailty in older adults. Teamwork related to the tool and CGA in primary care needs to be further investigated and developed.

Effect of hysterectomy on pain in women with endometriosis: a population-based registry study

OBJECTIVE

To assess pain symptoms before and after hysterectomy in women with endometriosis.

DESIGN

A population-based registry study.

SETTING

Sweden.

POPULATION

Women aged 18-45 years who underwent hysterectomy for endometriosis between 2010 and 2015.

METHODS

Pain symptoms before hysterectomy and 12 months after surgery were collected from the Swedish National Quality Register for Gynaecological Surgery (GynOp). Pain symptoms were also assessed by follow-up surveys after a median follow-up period of 63 months.

MAIN OUTCOME MEASURES

Pelvic or lower abdominal pain after hysterectomy.

RESULTS

The study included 137 women. The proportion of women experiencing pain of any severity decreased by 28% after hysterectomy (P < 0.001). The proportion of women with severe pain symptoms decreased by 76% after hysterectomy (P < 0.001). The majority of women (84%) were satisfied with the surgical result. Presence of severe pain symptoms after the hysterectomy was associated with less satisfaction (P < 0.001). Pain symptoms after surgery, patient satisfaction and the patient's perceived improvement were not significantly different between women whose ovarian tissue was preserved and women who underwent bilateral oophorectomy.

CONCLUSIONS

We observed a significant, long-lasting reduction in pain symptoms after hysterectomy among women with endometriosis. Hysterectomy, with the possibility of ovarian preservation, may be a valuable option for women with endometriosis who suffer from severe pain symptoms.

TWEETABLE ABSTRACT

Hysterectomy is a valuable option for women with endometriosis and severe pain symptoms.

Who needs to be “more equal” and why? Doing gender equality in male-dominated industries

Purpose

This study aims to deepen the understanding of inequality regimes in male-dominated industries, specifically in Swedish forestry and mining, by exploring how conceptions of gender, class and place are articulated and intertwined when doing gender equality in these organizations.

Design/methodology/approach

The article draws on empirical material from four research and development projects inspired by a feminist action research methodology.

Findings

This paper shows how gender equality works in these male-dominated organizations simultaneously constructing gender, class and place. When men are at the focal point of gender equality, our empirical findings suggest that blue-collar workers in rural areas are described as “being the problem” for gender inequality in these organizations. Addressing specific groups such as women or blue-collar workers in rural areas is not enough to challenge the inequality regimes that exist in these organizations, since a unilateral focus on certain groups leads to skewed problem formulations.

Originality/value

Research on gender equality work and its relation to intersectionality in male-dominated industries is limited, and by focusing on men and masculinities, this paper contributes to knowledge concerning gender equality in male-dominated industrial organizations.

A Theoretical Model for Urban Walking Among People With Disabilities

This paper is an attempt to advance research on walking at a neighborhood level of analysis for people with disabilities by proposing a theoretical model that combines the knowledge of two disciplines: traffic planning and environmental psychology. The aim is to provide guidance for a discussion and a plan for future interdisciplinary investigations by proposing a model that accounts for the dynamic interaction between environmental characteristics, human processes, and walking experience among individuals with a disability. For this purpose, traffic planners, and environmental psychologists came together to discuss theories, concepts, and thematic relevance in a series of focus group meetings. These meetings led to the selection of the Human Environment Interaction (HEI) model, originally developed from the field of environmental psychology and operationalized to describe how walking experiences result from the interplay between individual abilities, emotional processes, and the physical and social characteristics of the environment (Küller, 1991). The proposed model aims to sustain interdisciplinary discussion and research planning around the topic of neighborhood walking for people with disabilities. By operationalizing each dimension in the model, a good fit between groups with disabilities and individual differences associated with walking experiences is assumed, which, in turn, will have the potential to provide a more conscious analysis of wellbeing-related outcomes, such as usability of the environment, frequency of mobility, and quality of life. However, to improve understanding of urban walking at a neighborhood level for people with disabilities, empirical studies must be carried out to test the proposed model.

Enzymatic Determination of Free Glutamic Acid in Dried Soups and in Minced Sausages: NMKL1 Collaborative Study

An enzymatic method for the determination of free glutamic acid in meat products and dried soups was collaboratively studied in 11 laboratories. In the presence of the enzyme glutamate dehydrogenase, L-giutamic acid is oxidatively deaminated by nicotinamide adenine dinucleotide (NAD) to 2-oxoglutarate. In a reaction catalyzed by diaphorase, the NADH thus formed converts 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride to a formazan, which is measured in the visible range at 492 nm. Fourteen samples (7 samples of minced sausage and 7 samples of dried cauliflower soup) with glutamate contents varying between 0.4 and 16 g/kg were included In the study. Materials were distributed to participants as blind duplicates and as split level pairs. The mean relative standard deviation (RSDR) for reproducibility for the dried soup material containing glutamate between 7 and 16 g/kg was 4.6%. RSDR values for samples of minced sausage containing glutamate at lower levels (0.4-1.3 g/kg) were between 12 and 16%.

Integrated proteogenomic approach identifying a protein signature of COPD and a new splice variant of SORBS1

Translation of genomic alterations to protein changes in chronic obstructive pulmonary disease (COPD) is largely unexplored. Using integrated proteomic and RNA sequencing analysis of COPD and control lung tissues, we identified a protein signature in COPD characterised by extracellular matrix changes and a potential regulatory role for SUMO2. Furthermore, we identified 61 differentially expressed novel, non-reference, peptides in COPD compared with control lungs. This included two peptides encoding for a new splice variant of SORBS1, of which the transcript usage was higher in COPD compared with control lungs. These explorative findings and integrative proteogenomic approach open new avenues to further unravel the pathology of COPD.

Large carnivores and zoos as catalysts for engaging the public in the protection of biodiversity

Addressing the biodiversity crisis requires renewed collaborative approaches. Large carnivores are ambassador species, and as such they can aid the protection of a wide range of species, including evolutionarily distinct and threatened ones, while being popular for conservation marketing. However, conflicts between carnivores and people present a considerable challenge to biodiversity conservation. Our cross disciplinary essay brings together original research to discuss key issues in the conservation of large carnivores as keystone species for biodiversity rich, healthy ecosystems. Our findings suggest the need to promote coexistence through challenging ‘wilderness’ myths; to consider coexistence/conflict as a continuum; to include varied interest groups in decision making; to address fear through positive mediated experiences, and to explore further partnerships with zoos. As wide-reaching institutions visited by over 700 million people/year worldwide, zoos combine knowledge, emotion and social context creating ideal conditions for the development of care towards nature, pro-environmental behaviors and long-term connections between visitors and carnivores. Based on current research, we provide evidence that large carnivores and zoos are both powerful catalysts for public engagement with biodiversity conservation, recognizing barriers and suggesting future ways to collaborate to address biodiversity loss.

Determination of Lead, Cadmium, Zinc, Copper, and Iron in Foods by Atomic Absorption Spectrometry after Microwave Digestion: NMKL1 Collaborative Study

A method for determination of lead, cadmium, zinc, copper, and iron by atomic absorption spectrometry (AAS) after microwave digestion was subjected to a collaborative study in which 16 laboratories participated [including users of inductively coupled plasma (ICP) and ICP–mass spectrometry (MS)]. The types of samples included in the study were minced fish, wheat bran, milk powder, bovine and pig liver, mushroom, 2 simulated diets, and bovine muscle; the last 4 were certified reference materials. These were analyzed as single (4 samples), double blind (1 sample), or split level (2 samples) samples. Before the collaborative study, a pretrial was conducted in which 4 ready-made solutions and one fish tissue sample were analyzed for Pb and Cu. The reproducibility relative standard deviation (RSDR) values, for results above the detection limit, ranged from 59% at 0.155 mg/kg to 16% at 1.62 mg/kg for Pb, from 28% at 0.0124 mg/kg to 11% at 0.482 mg/kg for Cd, from 9.3% at 35.3 mg/kg to 1.7% at 147 mg/kg for Zn, from 39% at 0.241 mg/kg to 3.0% at 63.4 mg/kg for Cu, and from 17% at 7.4 mg/kg to 5.9% at 303 mg/kg for Fe. The RSDR values agreed well with the norms described by the International Union of Pure and Applied Chemistry. As a complement to the AAS determinations, a number of laboratories analyzed the samples either by ICP or by ICP–MS. The results of these analyses agreed well with the AAS results. On the basis of the results of the collaborative study, the method was adopted Official First Action by AOAC INTERNATIONAL.