Objectives:
The aim of this study was to assess the Dutch nationwide incidence of myelin oligodendrocyte glycoprotein (MOG)-IgG-associated acquired demyelinating syndromes (ADS) and to describe the ...clinical and serological characteristics of these patients.
Methods:
All serum samples for routine diagnostics from February 2014 to December 2017 were sent to the single central reference laboratory for the full-length MOG-IgG cell-based assay (CBA) in the Netherlands. Clinical data from patients known in our National ADS centre were available.
Results:
A total of 1414 samples of 1277 patients were received; of these, 92 patients (7%) were MOG-IgG-seropositive. The mean incidence was 0.16/100,000 people, with higher seropositivity in children (0.31/100,000) than in adults (0.13/100,000). In MOG-IgG-positive patients at the National ADS centre (61/92, 66%), the most common presenting phenotype is acute disseminated encephalomyelitis (ADEM, 56%) in children and optic neuritis (ON, 44%) in adults. Relapsing disease occurred in 9/34 (26%) children and 11/27 (41%) adults during median follow-up of 27.5 months. Patients were tested MOG-IgG-positive >200 months after the initial attack, suggesting an extended time to first relapse (TTFR). Longitudinal analysis of MOG-IgG (25/61, 41%) showed that 67% of the monophasic patients remain seropositive and 60% in relapsing patients. Majority of seronegative patients had no relapses (89%).
Conclusion:
This nationwide study shows that the overall incidence of MOG-IgG-seropositive disorders is 0.16 per 100,000 people. The distribution over the clinical phenotypes differs between adults and children. Seropositivity can be maintained over years even without clinical activity, while seronegative patients generally had no relapses.
Background:
Radiologically isolated syndrome (RIS) is typified by multiple sclerosis (MS)-like lesions on imaging, without clinical MS symptoms. The prevalence of pediatric RIS is largely unknown.
...Objective:
The objective of the study is to provide an estimated RIS prevalence in a population-based cohort of children.
Methods:
We used data from the Generation R study to identify the childhood RIS prevalence.
Results:
In 5238 participants, only one RIS case was identified (prevalence: 0.02%; 95% confidence interval (CI): 0.00–0.11). During a 62-month follow-up, imaging examinations showed accrual of new focal demyelinating lesions; however, no clinical MS symptoms occurred.
Conclusions:
This study shows that the occurrence of RIS in children from the general population is rare.
Fish species are known for their large phenotypic plasticity in life-history traits in relation to environmental characteristics. Plasticity allows species to increase their fitness in a given ...environment. Here we examined the life-history response of fish species after an abrupt change in their environment caused by the damming of rivers. Two reservoirs of different age, both situated on the Guiana Shield, were investigated: the young Petit-Saut Reservoir in French Guiana (14 years) and the much older Brokopondo Reservoir in Suriname (44 years). Six life-history traits in 14 fish species were studied and compared to their value in the Sinnamary River prior to the completion of Petit-Saut Reservoir. The traits analyzed were maximum length, absolute and relative length at first maturation, proportion of mature oocytes in ripe gonad, batch fecundity and mean size of mature oocytes. The results revealed a general increase of reproductive effort. All species showed a decrease in maximum length. Compared to the values observed before the dam constructions, eight species had larger oocytes and three species showed an increased batch fecundity. These observed changes suggest a trend towards a pioneer strategy. The changes observed in Petit-Saut Reservoir also seemed to apply to the 30 years older Brokopondo Reservoir suggesting that these reservoirs remain in a state of immaturity for a long time.
Peixes são conhecidos pela grande plasticidade fenotípica com que respondem às características do meio, o que lhes permite aumentar as chances de sucesso frente a variações ambientais. No presente trabalho foram examinadas as respostas biológicas de teleósteos após uma abrupta modificação no ambiente provocada pelo represamento dos rios. Dois reservatórios de diferentes idades, situados no norte da América do Sul, foram investigados: um mais jovem (14 anos), Petit-Saut, na Guiana Francesa, e outro mais antigo (44 anos), Brokopondo, no Suriname. Em 14 espécies de peixes foram avaliados seis atributos biológicos, os quais foram comparados com a situação apresentada no rio Sinnamary antes do enchimento do Reservatório Petit-Saut. Avaliamos o tamanho máximo dos indivíduos, os comprimentos absoluto e relativo de primeira maturação, a proporção de ovócitos maduros em gônadas desovantes, a fecundidade por lote, e o tamanho médio dos ovócitos maduros. Os resultados indicam ter havido aumento do esforço reprodutivo com a formação dos reservatórios. Todas as espécies tiveram redução de tamanho. Comparados aos valores observados antes da formação dos reservatórios, oito espécies tiveram ovócitos maiores e três espécies mostraram aumento da fecundidade por lote. A constatação dessas mudanças aponta para a adoção de estratégias de ocupação pioneira. Aquelas observadas no Reservatório Petit-Saut parecem também aplicar-se ao Reservatório Brokopondo, 30 anos mais antigo, sugerindo que esses reservatórios mantêm-se em condição imatura por muito tempo
The development of polymerization contraction stress was determined as a function of the surface area of porosity, so that the contribution of voids in resin composite to stress relief could be ...investigated. Experiments were carried out on 200-um-thick layers of resin bonded from wall to wall in a restrained condition. The resin samples were divided into three groups: Group A was without porosity, group B contained a small number of pores, and group C contained a large number of pores in comparison with group B. For each group, porosity area, maximal stress, and stress development rate were determined. The mean maximal stress and stress development rate were inversely proportional to the mean porosity surface. These characteristics differed significantly (p < 0.01) between group A and C. For determination of whether shrinkage stress reduction has to be ascribed to flow from the outer surfaces of the voids or to inhibition of the setting reaction by oxygen in the voids, resin containing only nitrogen bubbles was also tested. The results indicated that both aspects contributed substantially to shrinkage stress relief.
Incorporation of pores by the stirring of a luting cement contributes to stress reduction and can therefore be considered as a contribution to the maintenance of marginal integrity.
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