Expression of ephrinA5 during development and potential involvement in the guidance of the mesostriatal pathway

Identifying guidance cues that direct axon growth to their final connections during development is of crucial interest if we aim to repair circuits damaged in adulthood following neurodegenerative disorders or common traumatic injuries. In this work, we set out to determine the ephrinA5 guidance molecule involvement in the establishment of the mouse mesostriatal pathway during development. We showed, in vitro and in vivo, that a proportion of mesencephalic dopaminergic cells express the ephrinA5 receptor, EphA5. Moreover, we observed, using stripe assays, that ephrinA5 purified protein has a repulsive effect on most of the mesencephalic dopaminergic projections. In vivo, we detected rostro-caudal and ventro-dorsal ephrinA5 protein expression gradients in the vicinity of the dopaminergic axons in the ventral telencephalon and in the striatum, during the embryonic and early postnatal development. In addition, other EphA5 ligands were also detected in the mesostriatal pathway. Together, these expression patterns suggest that, ephrinAs and more specifically ephrinA5, may be actors in the guidance of dopaminergic projections. Further studies will focus on identifying the molecular specificity of these guidance cues, taking into account the mesencephalic dopaminergic heterogeneous neuronal population. This may help increase the integration of neuronal transplants in the mature lesioned brain or provide tools to re-establish mesostriatal circuits in vivo.     

Imaging of acetylcholine esterase activity in brainstem nuclei involved in regulation of sleep and wakefulness

Positron emission tomography with 11C-N-methyl-4-piperidyl-acetate (MP4A) was applied in eight healthy volunteers and two patients with mild Alzheimer's disease (AD) to assess acetylcholine esterase (AChE) activity in magnetic resonance imaging-identified brainstem nuclei. Uptake ratios in lateral dorsal tegmental and pedunculopontine nuclei relative to cerebellum yielded reproducible values for the AChE activity in controls and reduced values in AD, more marked in a patient with complaints of disturbed sleep. Cortical AChE activity was related to the extent of cognitive impairment which was more severe in the AD patient without sleep disturbance. This preliminary observational study demonstrates the feasibility to image and assess AChE activity in small nuclei of the brain stem. This approach may be helpful to investigate the interaction of various nuclei in the complex network regulating sleep and wakefulness in representative patient groups with documented sleep disturbance.     

Chronic intestinal pseudo-obstruction syndrome in pediatric patients.

The aim of this study was to report the presentation and outcome of 22 consecutive children (13 female) who presented with a syndrome of chronic intestinal pseudo-obstruction with or without urinary tract involvement. We analyse the main clinical and histopathological features and discuss therapeutic management. Ten patients had signs of intestinal obstruction at birth, in which 6 presented antenatally with megacystis on ultrasound. Six children presented with constipation and/or obstruction between 1 and 6 months of age and in 6 other patients diagnosis was made between the ages of 1 and 12 years. There was a family history in 4 patients. Investigations showed diffusely dilated gut on x-ray with slow transit on small bowel follow through. Absent or abnormal motor migrating complex with low amplitude contractions were demonstrated on duodeno-jejunal manometry in 12/13. Megacystis occurred in 15/21 and megaureter in 2/21. Full thickness biopsies (n = 22) revealed involvement of muscle layers in 8, and abnormal myenteric plexus on histochemistry in 13. In 1, the biopsies were inconclusive. Recurrent urinary tract infections occurred in all with structural urinary tract abnormality and most had bacterial overgrowth. Severe recurrent episodes of obstruction which required parenteral nutrition (PN) occurred in all patients. Drugs were unhelpful and decompression ileostomies or colostomies were performed in 20/22. Five children died from sepsis (n = 3) or sudden death. Eleven patients remain partially or totally dependent on PN despite decompression ileostomy in 10/11. Six patients underwent colectomy and ileorectal pull-through, 2 of which remain on long-term PN, while the others are totally orally fed. Despite careful histological study pointing to 2 main forms, myopathy and neuropathy, the etiology of primary intestinal pseudoobstruction syndromes remains unknown. It may present antenatally while most of the time the gut and the urinary tract are diffusely involved. The condition has a high morbidity with a percentage requiring long-term PN. Although the mortality rate is high (23%), careful treatment of urinary tract infections and bacterial overgrowth, decompression surgery and judicious use of PN allows survival to adult life.     

Monitoring of blood gases during extracorporeal circulation with an artificial lung

During cardiopulmonary bypass, the heart-lung machine and the patient's gas exchange systems (uptake and elimination) form an undissociable couple. Changes in one of the components lead to corresponding changes in the other. In the artificial lung, like in the natural lung and peripheral tissues, gas exchanges depend on several parameters: blood inlet conditions, blood flow rate, temperature, composition of the gas mixture used for ventilation, blood tissue perfusion, O2 consumption, etc. The perfusionist's primary objective is to obtain from the artificial lung adequate O2 delivery to and CO2 removal from the tissues. This paper discusses the main parameters which must be taken into account and analyses the main sensors currently available for in-line measurement of blood gases.     

FDG-Positron Emission Tomography and Invasive EEG: Seizure Focus Detection and Surgical Outcome

Summary: Purpose : To study the value of [¹⁸F]2-deoxyglucose (FDG)-positron emission tomography when surface ictal EEG is nonlocalizing.
Methods : FDG-PET scans were performed in 46 patients with complex partial seizures (CPS) not localized by ictal SUT-face-sphenoidal video-EEG (VEEG) telemetry. Interictal PET was performed with continuous EEG monitoring, and images were analyzed with a standard template. Forty patients subsequently had subdural and 6 had depth electrodes (invasive EEG, IEEG); 22 had bilateral implants. A focus was detected in 40, and 35 had temporal lobectomy based on IEEG localization.
Results : There was a close association between IEEG and PET localization (p < 0.01): 26 patients had relative unilateral temporal FDG-PET hypometabolism, all had congruent IEEG, and 18 of 23 were seizure-free after temporal lobectomy. Five patients had unilateral frontotemporal hypometabolism (3 of 5 were seizure-free), 1 had frontal hypometabolism, and 14 had no lateralized PET abnormality (4 of 7 were seizure-free). Patients who became seizure-free had significantly higher lateral temporal asymmetry index (AI). PET showed 315% relative temporal hypometabolism (AI) in 12 of 22 patients with non-lateralized surface ictal VEEG and was capable of distinguishing between frontal and temporal foci in 16 of 24 patients with lateralized, but not localized, surface ictal video-EEG.
Conclusions : FDG-PET provides valuable data in patients with unlocalized surface ictal EEG and can reduce the number of patients who require IEEG studies. Quantitation is necessary for optimal PET interpretation.     

肝豆状核变性基因第3-20号外显子突变及多态的DNA测序研究

肝豆状核变性（ＷＤ）是与铜代谢障碍有关的常染色体隐性遗传病。基因定位于１３ｑ１４．３，有２１个外显子，ｃＤＮＡ全长６．６４ｋｂ，编码１４６５个氨基酸的Ｐ型三磷酸腺苷（ＡＴＰ）酶，此酶参与铜跨膜转运的代谢过程。ＷＤ基因突变形式具有遗传异质性，欧洲人以１...     

Effects of antihypertensive treatment on the relaxation of the left ventricle in hypertensive patients

To increase our understanding of the interaction between anti-hypertensive drug therapy and left ventricular filling, 23 hypertensive patients (DBP 100 +/- 4 mmHg) had their myocardial mass measured and underwent gamma-angiography (determination of maximum volume of filling, MVF, end-diastolic volume/s-1, and the maximum time for filling, MTF, ms) before and after therapy with propranolol (100 mg/d), captopril (50 mg/d), nitrendipine (28 mg/day) or xipamide (20 mg/d). Blood pressure was recorded in the four treatment groups, and myocardial mass regressed only in those treated with propranolol or nitrendipine. Only the latter drug acts simultaneously on MVF (2.19 +/- 0.22 vs 2.47 +/- 0.43 EDV/s -1) and MTF (221 +/- 21 vs 192 +/- 20 ms) significantly (p less than 0.05). Xipamide only improved MTF (228 +/- 28 vs 209 +/- 20 ms; p less than 0.05). These data compared to those of the literature demonstrate the variability in the antihypertensive effects on ventricular filling, while its improvement may be proposed as a usual objective in treatment of hypertensive disease.