Kinetics and correlates of the neutralizing antibody response to SARS-CoV-2 infection in humans

1. Download : Download high-res image (164KB)
2. Download : Download full-size image

     

Foreword

Phytochemistry Reviews -     

Histopathological lesions of molluscs in the harbour of Norderney,Lower Saxony,North Sea (Germany)

During a combined research project at several stations along the Lower Saxony coast (German North Sea) antifouling biocides were analysed in water, sediment and biota. Pathological alterations in blue mussel, Pacific oyster and periwinkle found in the harbour of Norderney and a reference station are presented here and discussed on the background of chemical analyses. The molluscan species from the reference station Borkum East flat did not show any pathological effects in central organs, except those provoked by an infestation in the gastro-intestinal tract by the copepod Mytilicola intestinalis and trematode larvae. In most animals, the metacercaria were found in the interstitial tissue without any inflammatory reaction. In a minor number of specimens, an inflammatory reaction in the mucosa and sub-mucosa of the intestine occurred in association with Mytilicola infestation. These reactions may be evoked through mechanical irritation of the gut epithelium, metabolic products of the parasites or invading bacteria. In contrast to the observed pathological changes of mussels, oysters and periwinkles in Norderney harbour were not found to be associated with parasitic infestation. The most prominent pathological alterations were observed in the digestive system and in the gonad. In the gastro-intestinal tract inflammatory reactions, atrophy and necrosis of tubules in the mid gut gland were most pronounced in spring at the beginning of the pleasure boat season in the Pacific oyster and to a minor degree in the blue mussel and the periwinkle. The latter displayed additional inflammatory and necrotic processes in the gills. Especially in the gonad, an elevated resorption rate of gametes was present in the Pacific oyster and in the periwinkle. In addition, impact of organotin compounds was reflected in an intersex index of up to 1.4 in Littorina littorea in coincidence with masculinization of the reproductive organs.     

Tenascin-R promotes assembly of the extracellular matrix of perineuronal nets via clustering of aggrecan

Perineuronal nets (PNs) in the brains of tenascin-R-deficient (tn-r^−/−) mice develop in temporal concordance with those of wild-type (tn-r^+/+) mice. However, the histological appearance of PNs is abnormal in adult tn-r^−/− mice. Here, we investigated whether similar defects are also seen in dissociated and organotypic cultures from hippocampus and forebrain of tn-r^−/− mice and whether the structure of PNs could be normalized. In tn-r^−/− cultures, accumulations of several extracellular matrix molecules were mostly associated with somata, whereas dendrites were sparsely covered, compared with tn-r^+/+ mice. Experiments to normalize the structure of PNs in tn-r^−/− organotypic slice cultures by depolarization of neurons, or by co-culturing tn-r^+/+ and tn-r^−/− brain slices failed to restore a normal PN phenotype. However, formation of dendritic PNs in cultures was improved by the application of tenascin-R protein and rescued by polyclonal antibodies to aggrecan and a bivalent, but not monovalent form of the lectin Wisteria floribunda agglutinin. These results show that tenascin-R and aggrecan are decisive contributors to formation and stabilization of PNs and that tenascin-R may implement these functions by clustering of aggrecan. Proposed approaches for restoration of normal PN structure are noteworthy in the context of PN abnormalities in neurological disorders, such as epilepsy, schizophrenia and addiction.