Stroke in women — from evidence to inequalities

Stroke is the second largest cause of disability-adjusted life-years lost worldwide. The prevalence of stroke in women is predicted to rise rapidly, owing to the increasing average age of the global female population. Vascular risk factors differ between women and men in terms of prevalence, and evidence increasingly supports the clinical importance of sex differences in stroke. The influence of some risk factors for stroke — including diabetes mellitus and atrial fibrillation — are stronger in women, and hypertensive disorders of pregnancy also affect the risk of stroke decades after pregnancy. However, in an era of evidence-based medicine, women are notably under-represented in clinical trials — despite governmental actions highlighting the need to include both men and women in clinical trials — resulting in a reduced generalizability of study results to women. The aim of this Review is to highlight new insights into specificities of stroke in women, to plan future research priorities, and to influence public health policies to decrease the worldwide burden of stroke in women

Biokinetics of 90Sr after chronic ingestion in a juvenile and adult mouse model

The aim of our study was to define the biokinetics of 90Sr after chronic contamination by ingestion using a juvenile and adult murine model. Animals ingested 90Sr by drinking water containing 20 kBq l -1 of 90Sr. For the juvenile model, parents received 90Sr before mating and their offspring were killed between birth and 20 weeks of ingestion. For the adult model, 90Sr ingestion started at 9 weeks of age and they were killed after different ingestion periods up to 20 weeks. The body weight, food and water consumption of the animals were monitored on a weekly basis. Before killing and sampling of organs, animals were put in metabolic cages. 90Sr in organs and excreta was determined by liquid scintillation \textgreekb counting. Highest 90Sr contents were found in bones and were generally higher in females than in males, and 90Sr retention varied according to the skeletal sites. An accumulation of 90Sr in the bones was observed over time for both models, with a plateau level at adult age for the juvenile model. The highest rate of 90Sr accumulation in bones was observed in early life of offspring, i.e. before the age of 6 weeks. With the exception of the digestive tract, 90Sr was below the detection limit in all other organs sampled. Overall, our results confirm that 90Sr mainly accumulates in bones. Furthermore, our results indicate that there are gender- and age-dependent differences in the distribution of 90Sr after low-dose chronic ingestion in the mouse model. These results provide the basis for future studies on possible non-cancerous effects during chronic, long-term exposure to 90Sr through ingestion in a mouse model, especially on the immune and hematopoietic systems. © 2011 Springer-Verlag

Immune System Modifications Induced in a Mouse Model of Chronic Exposure to 90Sr

International audienceStrontium 90 (90Sr) remains in the environment long after a major nuclear disaster occurs. As a result, populations living on contaminated land are potentially exposed to daily ingesting of low quantities of 90Sr. The potential long-term health effects of such chronic contamination are unknown. In this study, we used a mouse model to evaluate the effects of 90Sr ingestion on the immune system, the animals were chronically exposed to 90Sr in drinking water at a concentration of 20 kBq/l, for a daily ingestion of 80-100 Bq/day. This resulted in a reduced number of CD19+ B lymphocytes in the bone marrow and spleen in steady-state conditions. In contrast, the results from a vaccine experiment performed as a functional test of the immune system showed that in response to T-dependent antigens, there was a reduction in IgG specific to tetanus toxin (TT), a balanced Th1/Th2 response inducer antigen, but not to keyhole limpet hemocyanin (KLH), a strong Th2 response inducer antigen. This was accompanied by a reduction in Th1 cells in the spleen, consistent with the observed reduction in specific IgG concentration. The precise mechanisms by which 90Sr acts on the immune system remain to be elucidated. However, our results suggest that 90Sr ingestion may be responsible for some of the reported effects of internal contamination on the immune system in civilian populations exposed to the Chernobyl fallout. © 2016 by Radiation Research Society

Absorbed radiation doses due to chronic ingestion of cesium-137 or strontium-90 by mice

The knowledge of the absorbed radiation dose is essential in order to interpret the results of animal experiments with chronic ingestion of radionuclides by rodents. In order to evaluate this absorbed dose, we applied the dose conversion factors proposed by ICRP publication 108 to mouse chronic ingestion experiments with 20 kBq.L-1 137Cs- or 90Sr-contaminated water. The results indicated that whole-body absorbed doses were 9 mGy and 10 mGy by the end of 20 weeks of 137Cs or 90Sr ingestion, respectively. These results of dose calculations were compared with results obtained with a more refined method using published organ-specific absorbed fractions of energy. There was good agreement between the two methods, indicating that, despite the simple hypotheses used to apply the ICRP 108 dose conversion factors to our mouse model, this method allows one to calculate in a simple and reliable way the absorbed radiation dose received by the rodents during long-term experiments on chronic ingestion of radionuclides

Chronic exposure to low concentrations of strontium 90 affects bone physiology but not the hematopoietic system in mice

International audienceThe aim of this work was to delineate the effects of chronic ingestion of strontium 90 (90Sr) at low concentrations on the hematopoiesis and the bone physiology. A mouse model was used for that purpose. Parent animals ingested water containing 20kBql-1 of 90Sr two weeks before mating. Offspring were then continuously contaminated with 90Sr through placental transfer during fetal life, through lactation after birth and through drinking water after weaning. At various ages between birth and 20weeks, animals were tested for hematopoietic parameters such as blood cell counts, colony forming cells in spleen and bone marrow and cytokine concentrations in the plasma. However, we did not find any modification in 90Sr ingesting animals as compared with control animals. By contrast, the analysis of bone physiology showed a modification of gene expression towards bone resorption. This was confirmed by an increase in C-telopeptide of collagen in the plasma of 90Sr ingesting animals as compared with control animals. This modification in bone metabolism was not linked to a modification of the phosphocalcic homeostasis, as measured by calcium, phosphorus, vitamin D and parathyroid hormone in the blood. Overall these results suggest that the chronic ingestion of 90Sr at low concentration in the long term may induce modifications in bone metabolism but not in hematopoiesis. Copyright © 2012 John Wiley andamp; Sons, Ltd

Is heart rate variability related to gait impairment in patients with Parkinson's disease? A pilot study.

Contains fulltext : 80070.pdf (publisher's version ) (Closed access)BACKGROUND AND PURPOSE: Impairments in gait and autonomic function are common in patients with Parkinson's disease (PD). These are likely independent symptoms, based on different etiologic mechanisms. However, a few recent reports have observed an association between motor function, in particular gait impairment, and autonomic function in PD. In those studies, the Unified Parkinson's Disease Rating Scale (UPDRS) was used to evaluate gait and motor function. The present study was performed to further examine this putative relationship using quantitative measures of autonomic function and gait in order to shed light on the underlying pathophysiology of these symptoms. METHODS: Nine healthy young, 15 healthy elderly and 18 PD patients were studied. Heart rate variability (HRV) measures were collected during rest. Gait speed, swing time and swing time variability were measured during a 1-min walk at comfortable speed. The motor portion of the UPDRS was also evaluated in all subjects. RESULTS: HRV values were highest in the young adults, intermediate in the healthy elderly controls, and lowest in the PD patients. Gait measures tended to deteriorate with age and were significantly worse in the PD patients, compared to the elderly controls. HRV was not correlated with any measure of gait performance (p>0.129) nor with the UPDRS-motor score (p>0.147). DISCUSSION AND CONCLUSIONS: The present findings support the idea that gait and autonomic function impairments co-exist in PD, but their etiology is based on distinct pathophysiological pathways, with minimal overlap

Prothrombotic factors do not increase the risk of recurrent ischemic events after cryptogenic stroke at young age: the FUTURE study

Contains fulltext : 193449.pdf (Publisher’s version ) (Open Access)BACKGROUND: The role of hypercoagulable states and preceding infections in the etiology of young stroke and their role in developing recurrent ischemic events remains unclear. Our aim is to determine the prevalence of these conditions in patients with cryptogenic stroke at young age and to assess the long-term risk of recurrent ischemic events in patients with and without a hypercoagulable state or a recent pre-stroke infection with Borrelia or Syphilis. PATIENTS AND METHODS: We prospectively included patients with a first-ever transient ischemic attack or ischemic stroke, aged 18-50, admitted to our hospital between 1995 and 2010. A retrospective analysis was conducted of prothrombotic factors and preceding infections. Outcome was recurrent ischemic events. RESULTS: Prevalence of prothrombotic factors did not significantly differ between patients with a cryptogenic stroke and with an identified cause (24/120 (20.0%) and 32/174 (18.4%) respectively). In patients with a cryptogenic stroke the long-term risk [mean follow-up of 8.9 years (SD 4.6)] of any recurrent ischemic event or recurrent cerebral ischemia did not significantly differ between patients with and without a hypercoagulable state or a recent infection. In patients with a cryptogenic stroke 15-years cumulative risk of any recurrent ischemic event was 24 and 23% in patients with and without any prothrombotic factor respectively. CONCLUSIONS: The prevalence of prothrombotic factors and preceding infections did not significantly differ between stroke patients with a cryptogenic versus an identified cause of stroke and neither is significantly associated with an increased risk of recurrent ischemic events after cryptogenic stroke