Optimization and Validation of a Human <i>Ex Vivo</i> Femoral Head Model for Preclinical Cartilage Research and Regenerative Therapies

OBJECTIVE: Articular cartilage is incapable of effective repair following injury or during osteoarthritis. While there have been developments in cartilage repair technologies, there is a need to advance biologically relevant models for preclinical testing of biomaterial and regenerative therapies. This study describes conditions for the effective ex vivo culture of the whole human femoral head. DESIGN: Fresh, viable femoral heads were obtained from femoral neck fractures and cultured for up to 10 weeks in (a) Dulbecco’s modified Eagle’s medium (DMEM); (b) DMEM + mixing; (c) DMEM + 10% human serum (HS); (d) DMEM + 10% HS + mixing. The viability, morphology, volume, and density of fluorescently labelled in situ chondrocytes and cartilage surface roughness were assessed by confocal microscopy. Cartilage histology was studied for glycosaminoglycan content using Alcian blue and collagen content using picrosirius red. RESULTS: Chondrocyte viability remained at >95% in DMEM + 10% HS. In DMEM alone, viability remained high for ~4 weeks and then declined. For the other conditions, superficial zone chondrocyte viability fell to 0.05). CONCLUSIONS: In this ex vivo model, chondrocyte viability was maintained in human femoral heads for up to 10 weeks in culture, a novel finding not previously reported. This human model could prove invaluable for the exploration, development, and assessment of preclinical cartilage repair and regenerative therapies

Intergenerational ties across borders: a typology of the relationships between Polish migrants in the Netherlands and their ageing parents

The question of how intergenerational relationships are maintained when family members reside in different countries has been gaining scholarly attention. However, those studies focus mostly on the so-called old migrant groups. The focus on the‘new migrants’from Central and Eastern Europe is still scarce. In this paper, we examine the transnational ties between Polish migrants in the Netherlands and their parents living in Poland. To identify types of transnational ties, we performed a latent class analysis using data on 970 men and women from the Families of Poles in the Netherlands (FPN) study. Following earlier studies on adult child–parent relationships in transnational context, we combined information on upward and downward emotional support,upward financial and practical support and frequency of contact (face-to-face and via communication technologies) and commitment to norms of filial obligation. Three types of transnational child–parent relationships were distinguished: harmonious, detached and obligatory. Multinomial regression analyses showed that background characteristics of the adult children and their parents rather than the time elapsed since arrival in the Netherlands accounted for variability in relationship type. The relatively high probability of face-to-face contacts even in detached ties is characteristic of the strong commitment to family life among people of Polish descent

Codebook of the families of Poles in the Netherlands (FPN) survey

Background of the survey The release of formal restrictions on the free movement of Central and Eastern Europeans that started with the end of the Cold War and the eastward enlargement of the European Union in the 2000s have led to new migration flows in Europe. Not surprisingly, the number of surveys carried out among migrants from former communist countries has increased significantly in recent years. These surveys, however, tend to focus on topics such as migration and job history, structural and socio-cultural integration in the host country, bonds with the country of origin or family formation and intermarriage. Insofar exchanges with family members are addressed, they tend to be about remittances to and frequency of contact with “the” family in the country that stayed behind. Information about migrants from Central and Eastern Europe regarding exchanges of money, practical support, emotional support with individual family members, background information on the family of origin, espoused family obligations, and marital and parenthood histories and well-being is scarce. The FPN survey was carried out to fill that void. In absolute terms, Poles are the largest group amongst emigrants from the Central and Eastern European countries which accessed the European Union in 2004. Estimates suggest that between 2004 and 2007, at least one million people emigrated from Poland. Among the top destination countries of Poles in Europe are Great Britain, Germany and the Netherlands. In the Netherlands, the annual number of Polish migrants currently entering the country is greater than the number of traditional migrant groups (Turks, Moroccans, Antilleans and Surinamese) taken together. There are more than 160,000 Poles in the Netherlands according to Statistics Netherlands

Uncovering hidden biodiversity in the Cryptophyta: Clone library studies at the Helgoland Time Series Site in the Southern German Bight indentifies the cryptophycean clade potentially responsible for the majority of its genetic diversity during the spring bloom.

Cryptophyceae are important group in marine phytoplankton, but little is known about the occurrence and distribution of individual species. Recently, with use of molecular probes and microarray technology, it has been shown that species related to teleaulax spp. or Chroomonas spp. (clades 4 or 6) contributed the most to cryptophycean biomass in the north Sea. for the microarray study, the single probe (clade 4/6) recognizes members of both clades 4 and 6 and thus cannot separate them. Therefore, it was unknown as to whether the cryptophyte community was composed of clade 4, clade 6 or both of them. Here, we addressed this question and increased the genetic diversity of our investigations of cryptophycean diversity in the north Sea by sequencing 18S rRnA clone libraries made from fractionated water samples to examine specifically the picoplanktonic fraction because that fraction was studied in detail in the earlier microarray study. We focused on samples from the spring phytoplankton bloom in 2004 because the microarray signals were the strongest at this time. Excluding chimeric sequences, we detect- ed nine cryptophycean oTUs, seven of which fell into the teleaulax/Plagioselmis branch, whereas two grouped with Geminigera spp. our results indicate that these oTUs, affiliated with clade 4, may be an important component of cryptophyte community during spring bloom in the north Se

Microstructural changes in the trigeminal nerve of patients with episodic migraine assessed using magnetic resonance imaging

Background: There is histological evidence of microstructural changes in the zygomaticotemporal branch of the trigeminal nerve in migraineurs. This raises the possibility that altered trigeminal nerve properties contribute to migraine pathophysiology. Whilst it is not possible to explore the anatomy of small trigeminal nerve branches it is possible to explore the anatomy of the trigeminal root entry zone using magnetic resonance imaging in humans. The aim of this investigation is to assess the microstructure of the trigeminal nerve in vivo to determine if nerve alterations occur in individuals with episodic migraine. Methods: In 39 migraineurs and 39 matched controls, T1-weighted anatomical images were used to calculate the volume (mm3) and maximal cross-sectional area of the trigeminal nerve root entry zone; diffusion tensor images were used to calculate fractional anisotropy, mean diffusion, axial diffusion and radial diffusion. Results: There were significant differences between the left and right nerve of controls and migraineurs with respect to volume and not cross-sectional area. Migraineurs displayed reduced axial diffusion in the right nerve compared to the left nerve, and reduced fractional anisotropy in the left nerve compared to left controls. Furthermore, although there were no differences in mean diffusion or radial diffusion, regional analysis of the nerve revealed significantly greater radial diffusion in the middle and rostral portion of the left trigeminal nerve in migraineurs compared with controls. Conclusions: Migraine pathophysiology is associated with microstructural abnormalities within the trigeminal nerve that are consistent with histological evidence of altered myelin and/or organization. These peripheral nerve changes may provide further insight into migraine pathophysiology and enable a greater understanding for targeted treatments of pain alleviation

Properties of Contextual Memory Formed in the Absence of αCaMKII Autophosphorylation

The alpha-isoform of calcium/calmodulin-dependent kinase II (αCaMKII) is a major synaptic kinase that undergoes autophosphorylation after NMDA receptor activation, switching the kinase into a calcium-independent activity state. This αCaMKII autophosphorylation is essential for NMDA receptor-dependent long-term potentiation (LTP), induced by a single tetanus, in hippocampal area CA1 and in neocortex. Furthermore, the αCaMKII autophosphorylation is essential for contextual long-term memory (LTM) formation after a single training trial but not after a massed training session. Here, we show that in the absence of αCaMKII autophosphorylation contextual fear conditioning is hippocampus dependent and that multi-tetanus-dependent late-LTP cannot be induced in hippocampal area CA1. Furthermore, we show that in the absence of αCaMKII autophosphorylation contextual LTM persists for 30 days, the latest time point tested. Additionally, contextual, but not cued, LTM formation in the absence of αCaMKII autophosphorylation appears to be impaired in 18 month-old mice. Taken together, our findings suggest that αCaMKII autophosphorylation-independent plasticity in the hippocampus is sufficient for contextual LTM formation and that αCaMKII autophosphorylation may be important for delaying age-related impairments in hippocampal memory formation. Furthermore, they propose that NMDA receptor-dependent LTP in hippocampal area CA1 is essential for contextual LTM formation after a single trial but not after massed training. Finally, our results challenge the proposal that NMDA receptor-dependent LTP in neocortex is required for remote contextual LTM

Codebook of the families of Poles in the Netherlands (FPN) survey

Background of the survey The release of formal restrictions on the free movement of Central and Eastern Europeans that started with the end of the Cold War and the eastward enlargement of the European Union in the 2000s have led to new migration flows in Europe. Not surprisingly, the number of surveys carried out among migrants from former communist countries has increased significantly in recent years. These surveys, however, tend to focus on topics such as migration and job history, structural and socio-cultural integration in the host country, bonds with the country of origin or family formation and intermarriage. Insofar exchanges with family members are addressed, they tend to be about remittances to and frequency of contact with “the” family in the country that stayed behind. Information about migrants from Central and Eastern Europe regarding exchanges of money, practical support, emotional support with individual family members, background information on the family of origin, espoused family obligations, and marital and parenthood histories and well-being is scarce. The FPN survey was carried out to fill that void. In absolute terms, Poles are the largest group amongst emigrants from the Central and Eastern European countries which accessed the European Union in 2004. Estimates suggest that between 2004 and 2007, at least one million people emigrated from Poland. Among the top destination countries of Poles in Europe are Great Britain, Germany and the Netherlands. In the Netherlands, the annual number of Polish migrants currently entering the country is greater than the number of traditional migrant groups (Turks, Moroccans, Antilleans and Surinamese) taken together. There are more than 160,000 Poles in the Netherlands according to Statistics Netherlands