Level of dependency: a simple marker associated with mortality during the 2003 heatwave among French dependent elderly people living in the community or in institutions

BACKGROUND: In France, the August 2003 heat wave was responsible for considerable excess mortality among the elderly. We wonder whether the dependency level could be a marker of the risk for mortality during this heat wave. METHODS: Retrospective cohort study of deaths that occurred between 1 and 20 August 2003, conducted in five departments in the Paris area (Ile-de-France) among the beneficiaries of the Allocation personnalisée d'autonomie (APA), a stipend specifically allocated to dependent subjects > or =60 years of age. Their dependency level was determined by the GIR group (defined by the French law) used to fix the APA amount. Subjects' GIR group classification and demographic variables were obtained from departmental administrative files. RESULTS: Among the 31,603 APA beneficiaries alive on 31 July 2003, 16,779 were community dwellers and 14,824 lived in institutions. Between 1 and 20 August 2003, 858 subjects died: 300 community dwellers and 558 institutionalised (mortality rates of 2.7, 1.8 and 3.8 per cent, respectively). Independent risk factors for mortality were: age, sex and GIR group in community dwellers; age, GIR group and living in a region highly exposed to heatwave mortality for institutionalised elderly; independent factors for mortality were age, sex, GIR group, type of residence (institution/community), living in a region highly exposed to heatwave mortality and income for the overall population. CONCLUSION: The dependency level was associated with mortality during the 2003 heatwave in France, especially for elderly community dwellers. Dependency might help identify high-risk subjects and guide targeted prevention measures against heatwave-associated mortality.     

Coherent neural representation of hand speed in humans revealed by MEG imaging

The spiking activity of single neurons in the primate motor cortex is correlated with various limb movement parameters, including velocity. Recent findings obtained using local field potentials suggest that hand speed may also be encoded in the summed activity of neuronal populations. At this macroscopic level, the motor cortex has also been shown to display synchronized rhythmic activity modulated by motor behavior. Yet whether and how neural oscillations might be related to limb speed control is still poorly understood. Here, we applied magnetoencephalography (MEG) source imaging to the ongoing brain activity in subjects performing a continuous visuomotor (VM) task. We used coherence and phase synchronization to investigate the coupling between the estimated activity throughout the brain and the simultaneously recorded instantaneous hand speed. We found significant phase locking between slow (2- to 5-Hz) oscillatory activity in the contralateral primary motor cortex and time-varying hand speed. In addition, we report long-range task-related coupling between primary motor cortex and multiple brain regions in the same frequency band. The detected large-scale VM network spans several cortical and subcortical areas, including structures of the frontoparietal circuit and the cerebello-thalamo-cortical pathway. These findings suggest a role for slow coherent oscillations in mediating neural representations of hand kinematics in humans and provide further support for the putative role of long-range neural synchronization in large-scale VM integration. Our findings are discussed in the context of corticomotor communication, distributed motor encoding, and possible implications for brain-machine interfaces.     

Increased renal responsiveness to vasopressin and enhanced V2 receptor signaling in RGS2-/- mice

The antidiuretic effect of vasopressin is mediated by V2 receptors (V2R) that are located in kidney connecting tubules and collecting ducts. This study provides evidence that V2R signaling is negatively regulated by regulator of G protein signaling 2 (RGS2), a member of the family of RGS proteins. This study demonstrates that (1) RGS2 expression in the kidney is restricted to the vasopressin-sensitive part of the nephron (thick ascending limb, connecting tubule, and collecting duct); (2) expression of RGS2 is rapidly upregulated by vasopressin; (3) the vasopressin-dependent accumulation of cAMP, the principal messenger of V2R signaling, is significantly higher in collecting ducts that are microdissected from the RGS2(-/-) mice compared with their wild-type littermates; and (4) analysis of urine output of mice that were exposed to water restriction followed by acute water loading revealed that RGS2(-/-) mice exhibit an increased renal responsiveness to vasopressin. It is proposed that RGS2 is involved in negative feedback regulation of V2R signaling.     

Right atrial metastasis from hepatocellular carcinoma

A 65-year-old patient with a past medical history of hypertension, alcoholism, micronodular cirrhosis, and coronary artery bypass grafting 10 years ago developed a hepatocellular carcinoma, treated by chemoembolization. One month after treatment, thoracoabdominal CT scan showed no residual hepatic tumor, but tumoral aspect in the right atrium with extension into the inferior vena cava. The patient being asymptomatic, cardiac ultrasound confirmed the presence of a free, mobile, pediculated tumor in the right atrium. Surgical exploration found a well-circumscribed mass, attached to the atrial wall by a 1.5-cm diameter pedicle implanted near the inferior vena cava ostium, moving freely in the right atrial cavity. The tumor was easily resected by section of the pedicle and its surrounding parietal implantation zone. No complications occurred postoperatively, and the patient was discharged on the 10th postoperative day. Three years after, the patient is in good health and is asymptomatic; cardiac ultrasound showed no tumor recurrence.     

Localization of electrodes in the subthalamic nucleus on magnetic resonance imaging

OBJECT: The authors describe a new method of localizing electrodes on magnetic resonance (MR) images and focus on the positions of both the most efficient contact and the electrode related to the MR imaging target. METHODS: Thirty-one patients who had undergone bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) were included in this study. Target coordinates were calculated in the anterior commissure-posterior commissure referential. A study of the correlation between the artifact and the related contact allowed one to deduce the contact position from the identification of the distal artifact on MR imaging. The best stimulation point corresponded with the contact resulting in the best Unified Parkinson's Disease Rating Scale (UPDRS) motor score improvement. It was compared (Student t-test) with the dorsal margin of the STN (DM STN), which was determined electrophysiologically. The distance between the target and the electrode was calculated individually in each axis. The best stimulation point was located at anteroposterior -2.34 +/- 1.63 mm, lateral 12.04 +/- 1.62 mm, and vertical -2.57 +/- 1.68 mm. This point was not significantly different from the DM STN (p < 0.05). The postoperative UPDRS motor score was 28.07 +/- 12.16, as opposed to the preoperative score of 46.27 +/- 13.89. The distance between the expected and actual target in the x- and y-axes was 1.34 +/- 1.02 and 1.03 +/- 0.76 mm, respectively. In the z-axis, 39.7% of the distal contacts were located proximal to the target. CONCLUSIONS: This approach proposed for the localization of the electrodes on MR imaging shows that DBS is most effective in the dorsal and lateral part of the STN and indicates that the DBS electrode can be located more proximally than originally expected because of the caudal brain shift that may occur during the implantation procedure.     

Clinical algorithm and resource use in the management of children with minor head trauma

Purpose

There are no clear guidelines for the management of minor head injury, including the use of skull x-rays and computed tomography (CT) scans of the head. This is reflected in clinical practice by a wide variability in imaging study use and by the fact that some patients are discharged home from the emergency room (ER), whereas others are admitted to the hospital with or without a period of observation before admission. To address this issue, we proposed and applied a new protocol for minor head injury at our institution.

Methods

Between January 2004 and December 2005, 417 patients presented to the emergency department at our institution with minor head injury. All of them had fallen from less than 1 m. Every chart was retrospectively evaluated, and pertinent data were extracted.

Results

The mean age of the patients was 9.8 months (2 weeks to 32 months). One hundred fifty-three had a skull x-ray, and 13 had a CT scan of the head. Of the 153 patients who had a skull x-ray, only 15 had a skull fracture. Of these 15 patients, 3 also had a CT scan of the head that confirmed the diagnosis of skull fracture. Of the 13 CT scans that were done, only these 3 were positive. Eleven patients were kept in the ER for 6 hours for close observation, and 5 of these were eventually admitted. Overall, 8 patients were admitted to the hospital for observation. Of these 8 patients, 7 had a skull x-ray, from which 5 were positive. Only 2 of the admitted patients had a CT scan, and they were both positive for a skull fracture. One of the CT also demonstrated a subdural hematoma along with subarachnoid hemorrhage. These 2 patients also had a positive skull x-ray. None of the patients that were admitted had headaches or neurologic impairments. The mean age of the patients admitted was 3.8 months (2 weeks to 12 months). The mean hospital stay was 1.2 days (1-3 days).

Conclusion

Only 10% of the skull x-rays and CT scans were positive for a skull fracture, which led to an admission in half of these patients. The other half was mainly discharged from ER after being observed. Several patients underwent a skull x-ray that we feel was not necessary in the management of their minor head injury. For those who had a head CT scan, only one revealed additional information and none of them had an impact on the final management. Observation in the ER could have been reasonable for most cases.     

Ultrastructural evidence that ependymal cells are infected in experimental scrapie

During the last stage of infection in the experimental scrapie-infected hamster model, light microscopy reveals typical immunostaining of PrPsc in the subependymal region and at the apical ependymal cell borders. Whereas the subependymal immuno-staining is known to originate from extracellular amyloid filaments and residual membranes of astrocytes as constituents of plaque-like structures, the ultrastructural correlate of the supraependymal PrPsc staining remains uncertain. To decipher this apical PrPsc immunopositivity and subsequently the ependymocyte-scrapie agent interaction, we employed highly sensitive immuno-electron microscopy for detecting PrPsc in 263K scrapie-infected hamster brains. The results revealed the supraependymal PrPsc signal to be correlated not only with extracellular accumulation of amyloid filaments, but also with three distinct ependymal cell structures: (1) morphologically intact or altered microvilli associated with filaments, (2) the ependymal cell cytoplasm in proximity of apical cell membrane, and (3) intracytoplasmic organelles such as endosomes and lysosomal-like structures. These findings suggest a strong ependymotrope feature of the scrapie agent and recapitulate several aspects of the cell-prion interaction leading to the formation and production of PrPsc amyloid filaments. Our data demonstrate that in addition to neurons and astrocytes, ependymocytes constitute a new cellular target for the scrapie agent. In contrast, the absence of PrPsc labeling in choroid plexus and brain vascular endothelial cells indicates that these cells are not susceptible to the infection and may inhibit passage of the infectious agent across the blood-brain barrier.     

Prevalence of risk factors for referring post-menopausal women for bone densitometry. The INSTANT study

BackgroundMeasurement of bone density by densitometry is an appropriate public health strategy for prevention of osteoporotic fractures in at-risk individuals, and physicians are encouraged to screen for these risk factors in post-menopausal women.ObjectiveTo determine the frequency of risk factors for osteoporosis in a representative sample of the French general population in order to estimate the number of women eligible for bone densitometry.MethodsA cross-sectional epidemiological survey of osteoporosis in 2081 post-menopausal women over 45 years in the general population was conducted using a stratified random sampling method and face-to-face interviews. Information was collected on personal or family history of vertebral fracture or limb fracture, endocrine disorders, corticosteroid use, and early menopause. Body mass index was determined during the interview by measuring height and weight.ResultsA total of 1041 women interviewed (51.8%) reported at least one risk factor for osteoporosis and would thus be eligible for densitometry. The most frequently reported risk factor was vertebral fracture or collapse (20.8%), followed by endocrine disorders (10.5%) and long-term corticosteroid treatment (10.5%). The prevalence of vertebral and limb fracture increased with age. Multiple risk factors were reported by 381 women and the proportion of women presenting multiple risk factors increased with age.ConclusionsExtrapolated to the general population, over five million women in France would be eligible for densitometry. Since only a small proportion of these currently receive a diagnosis of osteoporosis, a considerable number of women could thus potentially benefit from more widespread use of densitometry.     

RDPLF and Rein, 2 complementary registries: a comparison of the collected data

The 2 registries RDPLF and Rein are information systems concerning the treatment of end-stage renal disease. The aim of the study was to evaluate the representativeness and exhaustivity of the recorded cases as well as the accuracy of the informations in the 2 registries. Were included 375 adults, who started a first ESRD treatment between 1 January 2003 and 31 December 2003 in 7 French regions and were treated by peritoneal dialysis (PD) on the first day of the 4th month of ESRD treatment. 264 patients were identified found in both registries. Age, body mass index and albuminemia didn't differ significantly. The mean haemoglobin level was higher in RDPLF. There was a good concordance on sex, diabetes status but less so on primary renal disease and PD modalities. There were significant discrepancies between the two registries on the date of the first treatment. The analysis of outcomes (transplantation or death) showed 8 discrepancies related to the lack of recording of the event in one of the 2 registries. The good global agreement observed between Rein and RDPLF for the common data emphasizes the fiability and representativeness of the 2 structures and the synergy of their activities for a best evaluation of the quality of peritoneal dialysis. This study shows the necessity of a common patient identification that will allow us to maintain a good complementarity between the 2 registries and will favour common studies.