Prise en charge du patient avec bronchopneumopathie obstructive: ambulatoire ou hospitalière [Management of the patient with COPD: home case or hospitalization].

Acute exacerbation of COPD is one of the most common causes of hospital admission in patients affected with this disease. In most cases, consideration of differential diagnoses and assessment of important comorbidities will allow to make the decision whether or not the patient needs to be hospitalized. A decision to hospitalize will be based on specific symptoms and signs, as well on the patient's history. Contrary to bronchial asthma, a systematic action plan strategy is lacking for COPD. However, a disease management plan involving all the health care providers may have the potential to improve the patient's well being and to decrease costs related to these exacerbations.

CO-EXPRESSION OF GCDH AND OAT1 IN NEURONS AND PROXIMAL TUBULE CELLS

Tissue-specific expression studies of Glutaryl-CoA dehydrogenase (Gcdh) in adult rats revealed expression in the whole rat brain, almost exclusively in neurons, and surprisingly high expression in the juxtamedullar cortex of the kidney. The organic anion transporter 1 (OAT1) mediates basolateral uptake of glutarate derivatives from proximal tubule cells and contributes to their renal clearance. In brain, OAT1 is expressed at the choroid plexus, in neurons of cortex and hippocampus. We hypothesized that Gcdh and Oat1 are co-expressed in the same cells in kidney and brain and analyzed their mRNA expression by in situ hybridization on cryosections of adult rat brain, kidney and liver. In brain, Gcdh and Oat1 were found co-expressed in most neurons. Only the Purkinje neurons of the cerebellum were found to be Oat1 negative. In the kidney Gcdh and Oat1 are widely co-expressed with a specific high expression in proximal tubule cells. In conclusion there seems to be a functional coupling of Gcdh and Oat1 on a renal and neuronal level. Further studies are ongoing to confirm these findings in human tissues.

Co-evolution between sociality and dispersal: The role of synergistic cooperative benefits.

Explaining the evolution of sociality is challenging because social individuals face disadvantages that must be balanced by intrinsic benefits of living in a group. One potential route towards the evolution of sociality may emerge from the avoidance of dispersal, which can be risky in some environments. Although early studies found that local competition may cancel the benefits of cooperation in viscous populations, subsequent studies have identified conditions, such as the presence of kin recognition or specific demographic conditions, under which altruism will still spread. Most of these studies assume that the costs of cooperating outweigh the direct benefits (strong altruism). In nature, however, many organisms gain synergistic benefits from group living, which may counterbalance even costly altruistic behaviours. Here, we use an individual based model to investigate how dispersal and social behaviour co-evolve when social behaviours result in synergistic benefits that counterbalance the relative cost of altruism to a greater extent than assumed in previous models. When the cost of cooperation is high, selection for sociality responds strongly to the cost of dispersal. In particular, cooperation can begin to spread in a population when higher cooperation levels become correlated with lower dispersal tendencies within individuals. In contrast, less costly social behaviours are less sensitive to the cost of dispersal. In line with previous studies, we find that mechanisms of global population control also affect this relationship: when whole patches (groups) go extinct each generation, selection favours a relatively high dispersal propensity, and social behaviours evolve only when they are not very costly. If random individuals within groups experience mortality each generation to maintain a global carrying capacity, on the other hand, social behaviours spread and dispersal is reduced, even when the latter is not costly.

Silencing mutant ataxin-3 rescues motor deficits and neuropathology in machado-joseph disease transgenic mice.

Machado-Joseph disease (MJD) or spinocerebellar ataxia type 3 (SCA3) is an autosomal dominantly-inherited neurodegenerative disorder caused by the over-repetition of a CAG codon in the MJD1 gene. This expansion translates into a polyglutamine tract that confers a toxic gain-of-function to the mutant protein - ataxin-3, leading to neurodegeneration in specific brain regions, with particular severity in the cerebellum. No treatment able to modify the disease progression is available. However, gene silencing by RNA interference has shown promising results. Therefore, in this study we investigated whether lentiviral-mediated allele-specific silencing of the mutant ataxin-3 gene, after disease onset, would rescue the motor behavior deficits and neuropathological features in a severely impaired transgenic mouse model of MJD. For this purpose, we injected lentiviral vectors encoding allele-specific silencing-sequences (shAtx3) into the cerebellum of diseased transgenic mice expressing the targeted C-variant of mutant ataxin-3 present in 70% of MJD patients. This variation permits to discriminate between the wild-type and mutant forms, maintaining the normal function of the wild-type allele and silencing only the mutant form. Quantitative analysis of rotarod performance, footprint and activity patterns revealed significant and robust alleviation of gait, balance (average 3-fold increase of rotarod test time), locomotor and exploratory activity impairments in shAtx3-injected mice, as compared to control ones injected with shGFP. An important improvement of neuropathology was also observed, regarding the number of intranuclear inclusions, calbindin and DARPP-32 immunoreactivity, fluorojade B and Golgi staining and molecular and granular layers thickness. These data demonstrate for the first time the efficacy of gene silencing in blocking the MJD-associated motor-behavior and neuropathological abnormalities after the onset of the disease, supporting the use of this strategy for therapy of MJD.

MRI visualized neo-intimal dissection and co-localization of novel apoptotic markers apolipoprotein C-1, ceramide and caspase-3 in a Watanabe hyperlipidemic rabbit model

PURPOSE: Apoptotic arterial wall vascular smooth muscle cell death is known to contribute to plaque vulnerability and rupture. Novel apoptotic markers like apolipoprotein C-I have been implicated in apoptotic human vascular smooth muscle cell death via recruiting a neutral sphingomyelinase (N-SMase)-ceramide pathway. In vivo relevance of these observations in an animal model of plaque rupture has not been shown. METHODS AND RESULTS: Using Watanabe rabbits, we investigated three different groups (group 1, three normal Watanabe rabbits; group 2, six Watanabe rabbits fed with high cholesterol diet for 3 months; group 3, five Watanabe rabbits with similar diet but additional endothelial denudation). We followed progression of atherosclerosis to pharmacologically induced plaque rupture non-invasively using novel 3D magnetic resonance Fast-Field-Echo angiography (TR=7.2, TE=3.6 ms, matrix=512 x 512) and Fast-Spin-Echo vessel wall imaging methods (TR=3 heart beats, TE=10.5 ms, matrix=304 x 304) on 1.5 T MRI. MRI provided excellent image quality with good MRI versus histology vessel wall thickness correlation (r=0.8). In six animals of group 2/3 MRI detected neo-intimal dissection in the abdominal aorta which was accompanied by immuno-histochemical demonstration of concomitant aforementioned novel apoptotic markers, previously implicated in the apoptotic smooth muscle cell death in vitro. CONCLUSIONS: Our studies suggest a potential role for the signal transduction pathway involving apolipoprotein C-I for in vivo apoptosis and atherosclerotic plaque rupture visualized by MRI.

L'orientation du patient souffrant d'un syndrome douloureux abdominal aigu a domicile [Hospitalisation criteria for the acute abdominal pain patient seen at home or in an ambulatory setting].

Dealing at patient's home with an acute abdominal pain may be particularly challenging for the primary care physician. In such a clinical situation, the part of laboratory and radiological investigations is increasing in the diagnostic process. The decision to keep the patient at home based on a clinical evaluation alone may represent a great medical responsibility for the physician. Emergency departments (ED) are of course in charge of investigating such patients with a wide panel of investigation techniques. But these structures are chronically overcrowded resulting frequently in long and difficult periods of waiting. Based on a literature review, a description of useful clinical symptoms and signs is summarized and should help the decision process for the orientation of the patient.

Home and hospital treatment of acute seizures in children with nasal midazolam.

Rectal diazepam is widely used in the treatment of acute seizures in children but has some disadvantages. Nasal/sublingual midazolam administration has been recently investigated for this purpose but never at home or in a general paediatric hospital. The aim of this open study was to determine the efficacy, the tolerance and the applicability of nasal midazolam during acute seizures in children both in hospital and at home. We included known epileptic children for treatment at home and all children with acute seizures in the hospital. In all, 26 children were enrolled, 11 at home and 17 in the hospital (including two treated in both locations); only one had simple febrile seizure. They had a total of 125 seizures; 122 seizures (98%) stopped within 10 minutes (average 3.6 minutes). Two patients in the hospital did not respond and in three, seizures recurred within 3 hours. None had serious adverse effects. Parents had no difficulties administering the drug at home. Most of those who were using rectal diazepam found that nasal midazolam was easier to use and that postictal recovery was faster. Among 15 children who received the drug under electroencephalogram monitoring (six without clinical seizures), the paroxysmal activity disappeared in ten and decreased in three. Nasal midazolam is efficient in the treatment of acute seizures. It appears to be safe and most useful outside the hospital in severe epilepsies, particularly in older children because it is easy for parents to use. These data should be confirmed in a larger sample of children. Its usefulness in febrile convulsions also remains to be evaluated.

Liver enzyme elevation after lamivudine withdrawal in HIV-hepatitis B virus co-infected patients: the Swiss HIV Cohort Study.

Background The principal causes of liver enzyme elevation among HIV-hepatitis B virus (HBV) co-infected patients are the hepatotoxic effects of antiretroviral therapy (ART), alcohol abuse, ART-induced immune reconstitution and the exacerbation of chronic HBV infection. Objectives To investigate the incidence and severity of liver enzyme elevation, liver failure and death following lamivudine (3TC) withdrawal in HIV-HBV co-infected patients. Methods Retrospective analysis of the Swiss HIV Cohort Study database to assess the clinical and biological consequences of the discontinuation of 3TC. Variables considered for analysis included liver enzyme, HIV virological and immunological parameters, and medication prescribed during a 6-month period following 3TC withdrawal. Results 3TC was discontinued in 255 patients on 363 occasions. On 147 occasions (109 patients), a follow-up visit within 6 months following 3TC withdrawal was recorded. Among these patients, liver enzyme elevation occurred on 42 occasions (29%), three of them (2%) with severity grade III and five of them (3.4%) with severity grade IV elevations (as defined by the AIDS Clinical Trials Group). Three patients presented with fulminant hepatitis. One death (0.7%) was recorded. Conclusions HBV reactivation leading to liver dysfunction may be an under-reported consequence of 3TC withdrawal in HIV-HBV co-infected patients. Regular monitoring of HBV markers is warranted if active therapy against HBV is discontinued.

Peroxisome proliferator-activated receptors: finding the orphan a home.

The peroxisome proliferator-activated receptor (PPAR) is a member of the steroid hormone receptor superfamily and is activated by a variety of fibrate hypolipidaemic drugs and non-genotoxic rodent hepatocarcinogens that are collectively termed peroxisome proliferators. A key marker of peroxisome proliferator action is the peroxisomal enzyme acyl CoA oxidase, which is elevated about ten fold in the livers of treated rodents. Additional peroxisome proliferator responsive genes include other peroxisomal beta-oxidation enzymes and members of the cytochrome P450 IVA family. A peroxisome proliferator response element (PPRE), consisting of an almost perfect direct repeat of the sequence TGACCT spaced by a single base pair, has been identified in the upstream regulatory sequences of each of these genes. The retinoid X receptor (RXR) forms a heterodimer with PPAR and binds to the PPRE. Furthermore, the RXR ligand, 9-cis retinoic acid, enhances PPAR action. Retinoids may therefore modulate the action of peroxisome proliferators and PPAR may interfere with retinoid action, perhaps providing one mechanism to explain the toxicity of peroxisome proliferators. Interestingly, a variety of fatty acids can activate PPAR supporting the suggestion that fatty acids, or their acyl CoA derivatives, may be the natural ligands of PPAR and that the physiological role of PPAR is to regulate fatty acid homeostasis. Taken together, the discovery of PPAR has opened up new opportunities in understanding how lipid homeostasis is regulated, how the fibrate hypolipidaemic drugs may act and should lead to improvements in the assessment of human risk from peroxisome proliferators based upon a better understanding of their mechanism of action.

Home care: a safe and attractive alternative to inpatient administration of intensive chemotherapies.

OBJECTIVE: The objective of this study was to evaluate feasibility, safety, perception, and costs of home care for the administration of intensive chemotherapies. METHODS: Patients receiving sequential chemotherapy in an inpatient setting, living within 30 km of the hospital, and having a relative to care for them were offered home care treatment. Chemotherapy was administered by a portable, programmable pump via an implantable catheter. The main endpoints were safety, patient's quality of life [Functional Living Index-Cancer (FLIC)], satisfaction of patients and relatives, and costs. RESULTS: Two hundred days of home care were analysed, representing a total of 46 treatment cycles of intensive chemotherapy in 17 patients. Two cycles were complicated by technical problems that required hospitalisation for a total of 5 days. Three major medical complications (heart failure, angina pectoris, and major allergic reaction) could be managed at home. Grades 1 and 2 nausea and vomiting occurring in 36% of patients could be treated at home. FLIC scores remained constant throughout the study. All patients rated home care as very satisfactory or satisfactory. Patient benefits of home care included increased comfort and freedom. Relatives acknowledged better tolerance and less asthenia of the patient. Home care resulted in a 53% cost benefit compared to hospital treatment (420 ± 120/day vs. 896 ± 165/day). CONCLUSION: Administration of intensive chemotherapy regimens at home was feasible and safe. Quality of life was not affected; satisfaction of patients and relatives was very high. A psychosocial benefit was observed for patients and relatives. Furthermore, a cost-benefit of home care compared to hospital treatment was demonstrated.