Deep brain stimulation for Parkinson''s disease: electropermeabilization and activation

Deep brain stimulation, DBS, is an accepted technique for the treatment of Parkinson's disease. DBS affects the electrical functions of neurons, but exactly how it alters those functions is not clearly explained. An electrical model is determined to simulate treatment with DBS of the sub thalamic nucleus. This model shows the difference in electrical fields between the inside and the outside the neurons. The generated electrical field near the electrodes is high enough to perform an electropermeabilization of the cell membranes, which most likely blockade normal nerve pulses or reduce the nerve impulse speed. Further away from the electrodes activation of large axons is performed.     

El cultivo celular en la investigación básica del cáncer de mama

Resumen La técnica del cultivo celular es la que ha permitido conocer el comportamientoin vitro de las células cancerosas. En esta revisión pretendemos introducir las peculiaridades básicas del cultivo celular, referido especialmente a líneas cancerosas mamarias, relacionar el origen de las líneas celulares más utilizadas en la investigación de este cáncer, mencionar las técnicas de laboratorio que pueden aplicarse sobre estos cultivos y ejemplificar la utilidad de las mismas, tomando como modelo diversos trabajos que estudian los efectos del factor de crecimiento epidérmico sobre líneas celulares hormonoindependientes de cáncer de mama.      

DeGarengeot hernia: transabdominal preperitoneal hernia repair and appendectomy.

BACKGROUND: The incarcerated appendix in the femoral hernia represents a rare clinical case that was first described by the Frenchman de Garengeot in 1731. Besides the open procedures, laparoscopy presented itself as a treatment option. CASE REPORT: Our case concerns a 38-year-old patient with a right femoral hernia with an inflamed incarcerated appendix. Because of the clinically inconclusive finding, we chose transperitoneal preperitoneal hernia repair (TAPP) combined with a laparoscopic appendectomy. The intra- and postoperative course was uneventful. This case shows that a laparoscopic procedure is possible even in the case of an incarceration in conjunction with an appendicitis that has not spread to the adjacent peritoneum. DISCUSSION: Compared with open interventions, the subjective social advantages (shorter hospital stay, earlier return to work, less need for pain killers, and others) of laparoscopic hernia treatment have been extensively studied. The use of both methods in the case of an incarcerated hernia is open to dispute, though various small series confirm the feasibility. CONCLUSION: Here, TAPP seems to be the more reliable method in terms of patient safety because of the simultaneous possibility of using laparoscopy.     

Neurophysiological aspects of chronic motor cortex stimulation

Chronic motor cortex stimulation is a treatment option for neuropathic drug-resistant pain and possibly associated movement disorders. Preliminary studies suggest the possibility to treat symptoms of Parkinson disease in selected patients. Recently, MCS has been suggested to enhance motor recovery in patients with poststroke hemiparesis. One or more electrodes are placed extradurally over the motor cortex through a burr hole or a small craniotomy, and then connected to a totally implantable neurostimulator. The accurate positioning of the stimulating electrodes over the motor cortex is the key point of the surgical procedure. Motor cortex identification results from the integration of anatomical, neuroradiological, functional, and neurophysiological data, taking into account the huge population variability. Intraoperative neurophysiological mapping of the motor cortex is of paramount importance, in spite of very sophisticated neuroradiological mathematical reconstructions of the motor area. We discuss and compare the different techniques that are utilized by different authors. Moreover, clinical neurophysiology is also helpful in evaluating the results of this neuromodulation procedure and in hypothesizing the mechanisms that are put in play by MCS.     

Measurement of contact impedance of electrodes used for deep brain stimulation

High frequency electrical stimulation by means of electrodes implanted into the brain has become an accepted technique for treatment of Parkinson's disease. The electrical field distribution normally inserted into the sub thalamic nucleus minimise abnormal brain activity. Square wave pulses of 1–3.6 V with duration of 60–90 μs at a frequency range of 130–185 pps are generally used. Every electrode unit consists of four cylindrical electrodes positioned in a row and can be switched on independently. This paper determines the contact impedance of the electrodes for different frequencies and proposes improvement to reduce the contact impedance between the electrodes and the brain. Measurements were performed by placing the electrodes in a tank filled with saline. Different frequencies were applied on two electrodes via a resistor. The current was measured through the resistor and the voltage was registered between one of the electrodes and a third non current carrying electrode. The obtained values were used to calculate the contact impedance. The result shows large contact impedance for the used frequency compared to the impedance of the treated tissue, which means that variation in contact impedance can result in variation in the electrical field applied to the tissue.     

Les formes psychiatriques de la maladie de Niemann-Pick de type C

Niemann-Pick type C disease diagnosed in adult neurology departments may be infantile or juvenile forms with prolongated life spans or forms starting at adolescence or adulthood. Psychomotor retardation is practically constant. In some cases, a psychosis may be the only manifestation for several years. The diagnosis is often made when extrapyramidal symptoms appear as well as cerebellar ataxia and ophtalmoplegia in the vertical gaze. The treatment with psychotropic drugs raises the question of a superimposition of a drug induced lipidosis. Hepatosplenomegaly is often discrete contrary to classical infantile cases. Foam cells as well as sea blue histiocytes are features of the disease. The filipin test evidences the lysosomal storage of cholesterol.     

Le suicide par saut et les stratégies de prévention

The topic of this article is to probe into the specificities of suicide by jumping. This means of suicide hasn't been studied much and isn't well known yet.We reviewed the international scientific literature so as to take an in-depth look at this type of auto-aggressive action and highlight the characteristics of the subjects likely to commit suicide by jumping. We thus focus on the available epidemiological data and risk factors associated to suicide jumping. We also describe the prevention strategies most often evoked to deal with this public health issue, which are respectively about improving safety on the identified suicide sites and providing medical and psychological care to individuals likely to commit suicide by jumping.This meta-analysis presents our critical analysis of the methodological limits in the studies exposed. We provide further hints for researching this field of study; they're based on both the taking into account of variables that could be risk factors for this particular means of suicide and the evaluation of the efficiency for the preventive measures used.     

Medium term outcome for infant repair in tetralogy of Fallot: indicators for timing of surgery

Objective: To assess the impact of early corrective surgery on the short and medium term outcome in tetralogy of Fallot (TOF). Materials and methods: All patients under 12 months of age undergoing correction of isolated TOF between February 1997 and July 2003 were reviewed retrospectively. Outcome data for mortality, post-operative care management, major morbidity and clinical follow-up were analysed. Results: Fifty-two operations were performed. The mean age at surgery was 5 months (range 1–12) of whom 16 (30.8%) were less than 3 months old, including 2 neonates, 22 (42.3%) were 3–6 months old and 14 (26.9%) were 7–12 months old. There was 1 (1.9%) early death caused by a cerebro-vascular accident and 1 (1.9%) late death secondary to acute infective endocarditis. There were no differences in post-operative morbidities attributable to age. Patients under 3 months old required greater duration of post-operative ventilation, ITU stay and in-hospital stay. At a mean follow-up of 4.0 years (range 1.5–8.0), 33 (63.5%) patients had well-tolerated pulmonary regurgitation (PR) and 3 (5.8%) patients required re-operation for right ventricular outflow tract obstruction (RVOTO). All patients had right bundle-branch-block but with QRS < 150 ms. Conclusion: Early definitive repair of TOF can be performed safely on patients under 6 months old. Age at surgery does not appear to affect the medium term haemodynamic outcome. However, early surgery does escalate the need for ICU care. This data suggests repair in asymptomatic patients be delayed until 3–6 months of age.     

La fonctionnalité alimentaire : illusion aujourd’hui, réalité demain

Foods have always been considered by man as a means of ensuring his physiological needs, allowing the growth, development and preservation of the body and its tissues (nutritional value of food). To this can be added the feelings of satisfaction and well-being that food gives to its consumer, thus constituting an element that is fundamental for our physiological and mental balance (the sensorial value of food).Nevertheless, recent scientific studies have shown that over and above the ensuring of nutritional needs, eating habits can also adjust certain functions of the human organism and thus play a beneficial or harmful role on one's health (the functional value of food).The whole concept of nutrition has been enriched by the notion that eating is not only a survival reflex (satisfaction derived through eating and the avoidance of harmful effects due to eating deficiencies or excesses): eating aims to improve one's health and well-being and to reduce the risk of developing various pathologies. These new data open interesting new horizons in today's context where health is increasingly expensive and people are increasingly concerned to improve their quality of live.     

法乐四联症右室心肌超微结构定量测量与临床的对比研究

为探讨法乐四联症（Ｆ_４）右室心肌超微结构的不同表现与Ｆ_４术前各项临床检查及术后心功能的关系，作者对室间隔缺损组（Ⅰ组，１１例），儿童Ｆ_４组（Ⅱ组，１３例）和成人Ｆ_４组（Ⅲ组，１３例）进行比较，用Ｓｙｓｔａｔ计算机统计软件作多因素方差分析和Ｐｅａｒｓｏｎ相关研究。结果见Ⅱ、Ⅲ组病人的ＰＯ_２仅和核浆比有关，Ｐ_（ＲＶ）与细胞的核体密度、横径、核浆比及肥大肌细胞比率明显有关，肥大肌细胞比率与病人年龄及ＰａＯ_２明显相关。作者认为Ｆ_４病人右室心肌超微结构改变主要系右室压力增高所致，这种改变与年龄有关。