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C Arnaud

Publications and source records attributed to C Arnaud.

At least 19 recordsLinked to original sources
PubMed2006

Habenula lesions alter synaptic plasticity within the fimbria-accumbens pathway in the rat.

Both the habenula and the nucleus accumbens, and especially the glutamatergic innervation of the latter from the hippocampus, have been hypothesized to be involved, in different ways, in the pathophysiology of cognitive disturbances in schizophrenia. Lesions of the habenula produce disturbances of memory and attention in experimental animals. As the habenular nuclei have been shown to influence the release of many neurotransmitters, both in the hippocampus and the nucleus accumbens, we examined in this study the effects of bilateral habenula lesions on the plasticity of the fimbria-nucleus accumbens pathway, by means of the long-term depression phenomenon in freely moving rats. Long-term depression, induced within the shell region of the nucleus accumbens by low-frequency stimulation of the fimbria, was exaggerated and showed greater persistence in habenula-lesioned rats compared with sham-operated animals. These results indicate that plasticity in the fimbria-nucleus accumbens pathway is altered by habenula lesions in a way similar to previously-reported effects of stress and the psychosis-provoking agent ketamine. Moreover, they strengthen the views that the habenula belongs to systems, mediating higher cognitive functions, which involve the hippocampus and the nucleus accumbens. Finally, this study suggests that dysfunction of the habenula could contribute to cognitive alterations in diseases such as schizophrenia, where the habenula is reported to exhibit exaggerated calcification.

Analysis of Variance↗
PubMed2005

Do new therapeutic approaches (autotransplants, thalidomide, dexamethasone) improve the survival of patients with multiple myeloma followed in a rheumatology department?

Survival of patients with multiple myeloma (MM) showed no improvement between the 1960s and 1990s. During the last decade, new therapeutic approaches seemed likely to offer hope of prolonging survival. The aim of this study was to examine if this survival increased with the usage of new treatments. The method involves a retrospective study of 123 patients with MM, diagnosed between 1975 and 1999, all receiving treatment. They were divided into two groups: group 1 included 55 patients given the so-called "old treatments" [melphalan-prednisone, cyclophosphamide-prednisone, polychemotherapy (vincristine, melphalan, cyclophosphamide, prednisone (VMCP), VMCP-VBAP)], and group 2 included 68 patients receiving at least one of the so-called "new treatments" (dexamethasone, thalidomide, high-dose chemotherapy followed by autotransplants, bisphosphonates, interferon). The two groups were similar in terms of age, sex ratio and renal impairment, and the percentage of light-chain MM was identical in both groups. Patients who had been given a "new" treatment (group 2) had longer median survival than the patients in group 1 (54 vs 42 months). Independent analysis of each treatment modality showed increased median survival in MM patients treated using autotransplantation compared with untreated patients (125 vs 45 months). Survival was also longer in MM patients treated with thalidomide than in untreated patients (72 vs 42 months). On the other hand, neither bisphosphonates, interferon-alpha nor dexamethasone result in improved survival. Our findings emphasize the increased survival of the MM patients treated with new therapeutic approaches.

Adult↗
PubMed2005

[Retinal detachment by inferior tear: a poor prognosis?].

AIM: To determine whether a lower location of retinal wounds is a factor for poor prognosis in retinal detachment. PATIENTS AND METHOD: This retrospective study involved 248 medical records of patients who were operated on for retinal detachment in 2001 at the Toulouse-Rangueil Hospital Ophthalmology Department. We excluded retinal detachment of very short-sighted patients, diabetic patients and detachment secondary to trauma or relapses. We compared the incidence of surgical failure according to various parameters: condition of the crystalline lens, operative technique, operator, vitreoretinal proliferation, retinal wound location, patient age and the operative side. Thirty-six patients presented with lower wounds; 17 patients obtained incomplete results and relapsed within 1 year of surgery. RESULTS: Vitreoretinal proliferation and inferior location of the retinal detachment were found to be poor prognostic factors. No significant differences were found between the other parameters studied. DISCUSSION: A variety of prognostic factors of retinal detachment surgery are now clearly identified (vitreoretinal proliferation, old detachment). A lower location of the detachment constitutes an additional difficulty for retinal applications. Indeed, it is more difficult to perform effective buffering in this type of case. We recommend that retinal detachment be operated internally, to reduce the risk of relapse. CONCLUSION: An inferior location of the retinal wound during retinal detachment appears to be a factor of poor prognosis, but this remains to be ascertained through an ongoing, prospective study.

Female↗
PubMed2005

[Socioeconomical status, health behaviors and health status of French adolescents: Health Behavior in School-aged Children (HBSC) survey].

BACKGROUND: The impact of living conditions on health is not well known, but health inequalities observed in adults seem partly determined by behaviours and health status at an earlier stage, and more particularly during adolescence. So, our aim was to study adolescents' health and their health behaviours function to family socioeconomic status. METHODS: We analysed French data from the international survey "Health Behavior in School-aged Children" carried out in a representative sample of adolescents aged 13 and 15 years in 1998. A self-administered questionnaire was completed by the adolescents who answered questions concerning their health, health behaviours, and their families' socio-economic status. RESULTS: Adolescents from blue-collar families were more numerous to report to be in "fairly good health" or "not very good health" (OR = 1.40, CI 95% = 1.12-1.74) and to be overweight or obese (OR = 1.85, CI 95% = 1.25-2.24) than those from executive families. They were also more numerous to have bad health behaviours than those from executive families. CONCLUSION: This study has established that, in adolescents, differences in health, health behaviours, types of consumption and physical activities depended on the families' socio-economic status.

Adolescent↗
PubMed2005

Case gender and severity in cerebral palsy varies with intrauterine growth.

BACKGROUND: There is an unexplained excess of cerebral palsy among male babies. There is also variation in the proportion of more severe cases by birth weight. It has recently been shown that the rate of cerebral palsy increases as intrauterine size deviates up or down from an optimum about one standard deviation heavier than population mean weight-for-gestation. AIMS: To determine whether the gender ratio or the severity of cases also varies with intrauterine size. METHODS: A total of 3454 cases of cerebral palsy among single births between 1976 and 1990 with sufficient data to assign case severity (based on intellectual impairment and walking ability) and to compare weight-for-gestation at birth to sex specific fetal growth standards, were aggregated from nine separate registers in five European countries. RESULTS: The greater the degree to which growth deviates either up or down from optimal weight-for-gestation at birth, the higher is the rate of cerebral palsy, the larger is the proportion of male cases, and the more severe is the functional disability. Compared to those with optimum growth the risk of more severe cerebral palsy in male babies is 16 times higher for those with a birth weight below the 3rd centile and four times higher when birth weight is above the 97th centile. In contrast, for mild cerebral palsy in female babies the excess risks at these growth extremes are about half these magnitudes. CONCLUSIONS: Among singleton children with cerebral palsy, abnormal intrauterine size, either small or large, is associated with more severe disability and male sex.

Birth Weight↗
PubMed2005

Pleiotropic effects of statins in atherosclerosis: role on endothelial function, inflammation and immunomodulation.

Atherosclerosis and its complications still represent the major cause of death in developed countries. Statins have been described as the most potent class of drugs to reduce serum cholesterol levels. The effectiveness and rapidity of statin-induced decreases in coronary events led to the speculation that statins possess also cholesterol-independent effects. By the inhibition of 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase, an enzyme crucial to cholesterol synthesis, statins reduce not only cholesterol but also non steroidal isoprenoid intermediates production. Since these isoprenoids, such as farnesyl pyrophosphate and geranylgeranyl pyrophosphate, regulate the small signaling proteins, Ras and Rho, inhibition of these prenylated proteins by statins might account for their non-lipid-related effects. In this review, we describe the numerous beneficial pleiotropic effects of statins that could modulate atherogenesis.

Arteriosclerosis↗
PubMed2004

Re-hospitalization in infants younger than 29 weeks' gestation in the EPIPAGE cohort.

AIM: To estimate the re-hospitalization rate of extremely preterm children during infancy and associated factors after the recent improvement in survival rates. METHOD: The cohort included all children born before 29 wk of gestation in nine French regions in 1997. All admissions between discharge from initial hospitalization and 9 mo after birth were considered. Factors studied included the child's characteristics at birth and during neonatal hospitalization, risk factors for infection after discharge and parents' socio-demographic characteristics. Adjusted odds ratios (aOR) for re-hospitalization for all reasons and for respiratory disorders were obtained from logistic regression models. RESULTS: Of the 376 children, 178 were re-admitted at least once (47.3%; 95% CI: 42.3-52.4). Fifty-five percent of the hospitalized children were admitted at least once for respiratory disorders. The re-hospitalization rate was higher for children who had had chronic lung disease (aOR: 2.2; 95% CI: 1.3-3.7), those initially discharged between August and October (aOR: 2.5; 95% CI: 1.2-5.1) or between November and January (aOR: 3.2; 95% CI: 1.5-6.8), and children living with other children under six (aOR: 3.4; 95 %CI: 1.6-7.5). Re-hospitalizations were associated with neither gestational age nor the duration of neonatal hospitalization. Adjusted odds ratios for re-hospitalization for respiratory tract disorders were very similar to those for the overall hospitalizations. CONCLUSION: Infants born before 29 wk have a very high risk of re-hospitalization. The associated factors can help define high-risk groups at discharge from the neonatal unit who need special surveillance.

Adult↗
PubMed2004

Protective effect of cicletanine on renal function in diabetic spontaneously hypertensive rats.

Hypertension and diabetes are commonly associated and strongly predispose to renal injuries. In general, antihypertensive therapies protect from these damages, but the effect of cicletanine, a new type of antihypertensive drug, is unknown. This study examines the effects of cicletanine on renal failure in spontaneously hypertensive rats with diabetes (SHRD). Diabetes mellitus was induced with streptozotocin in uninephrectomized SHR. Rats received the vehicle, 10 mg or 50 mg/kg per day of cicletanine for 6 weeks. Age-matched untreated Wistar-Kyoto rats were used as controls. Systolic blood pressure (SBP), microalbuminuria and proteinuria were assessed throughout the treatment. At the end of the study, creatinine clearance measurements and histological analysis of kidneys were performed. Cicletanine did not affect SBP but decreased the elevated albuminuria of diabetic SHR in a dose-dependent manner. Similar results were obtained for proteinuria. Treatment with the high dose of cicletanine also normalized the altered creatinine clearance of diabetic SHR. These results indicate that cicletanine has a renal-protective action, probably blood pressure-independent, in a model combining hypertension and diabetes. The mechanism of renal-protection of cicletanine is not clearly established but may be due to the stimulation of arterial prostacyclin synthesis and/or to the reduction of intraglomerular capillary pressure.

Albuminuria↗
PubMed2002

[Botulinum toxin in the management of spastic hip adductors in non-ambulatory cerebral palsy children].

PURPOSE OF THE STUDY: Spasticity of the hip adductors is a challenging problem for children with severe motor impairment due to cerebral palsy. It inhibits motor development and is also a risk factor for hip dislocation. Botulinum toxin has been found to be an effective means of treating spastic pes equinus in walking cerebral palsy patients and could have other indications. We conducted a prospective study to determine the functional and orthopedic contribution of botulinum toxin in the treatment of spastic hip adductors in non-ambulatory cerebral palsy children. MATERIAL AND METHODS: The study included 11 quadriplegic children with cerebral palsy (mean age 5 years 9 months). Seven of the children had unilateral migration of the hip at study onset (> 40% radiographically). The children were given a single injection of botulinum toxin (Dysport: 20 units/kg/hip) in the adductor muscles (21 treated hips). The children were seen again at months 1, 3, 6 and 12 after treatment (with the exception of one patient not seen after the 6(th) month at the request of the parents). Spasticity was measured with the modified Ashworth scale. The motor level was determined with 8 position and motor items and with the GMFCS classification. Hip x-rays were obtained at study onset and once or twice during the follow-up. RESULTS: There were no adverse effects of the treatment. Spasticity decreased by one point or more on the Ashworth scale in 20 hips at month 1 and remained low at month 3 in 14, and at month 6 in 12 of the 21 hips treated. The effect of the anti-spasticity treatment faded out from the 6(th) to the 12(th) month. Three children who experienced pain in the lower limbs were definitively relieved after treatment. Nine children achieved functional improvement (progress in at least one of the motor items). Three children were able to walk with a walker and two of them improved from level IV to level III on the GMFCS. The best functional responses appeared to occur in the younger children and in those who had good results at months 3 and 6. Among the 7 children whose hip was displaced by more than 40%, 5 had an unfavorable radiological progression and underwent surgery. DISCUSSION: This study demonstrates that the botulinum toxin can be effective against spasticity of the hip adductors and that its effect is still significant 6 months after the injection in more than half the hips treated. It has an analgesic effect. This treatment has a functional impact even in children with severe motor impairment. The benefit has been modest but three children were able to progress to walking with a walker. The best functional results were observed in the younger children and in those whose spasticity had declined at month 3 and 6. It could thus be favored either by innate potential for motor development or by the treatment itself. The botulinum toxin did not improve the orthopedic prognosis of the children: 5 of the 7 with a risk of luxation worsened. Nevertheless, our study suggests that the botulinum toxin is a well-tolerated anti-spasticity treatment that is effective for the hip adductors providing an important contribution to the management of non-ambulatory cerebral palsy children.

Adolescent↗
PubMed2001

Study of a GABAC receptor antagonist on sleep-waking behavior in rats.

RATIONALE: gamma-Aminobutyric acid (GABA) is the main inhibitory transmitter of the brain. The involvement of GABAA and GABAB receptors in sleep-waking processes is well established. OBJECTIVES: This research studied the influence of GABAC receptors. METHODS: The rats were randomly infused in the fourth ventricle with vehicle and 25, 50, and 100 micrograms (1,2,5,6,-tetrahydropyridine)-methylphosphinic acid (TPMPA), a specific antagonist of GABAC receptors. RESULTS: Principally at 50 micrograms, the molecule induced an increase of waking from 44.7% to 61.7% (P < 0.003), which was the consequence of enhancement of both active and quiet wakefulness. Total slow wave sleep was decreased, particularly the slow-wave stage from 39% to 27.7% (P < 0.02). Paradoxical sleep was also decreased from 14.5% to 9.1% (P < 0.01). CONCLUSIONS: GABAC receptors are also involved in sleep-waking regulation. Since the sensitivity of GABAC receptors to GABA is much higher than that of GABAA and GABAB receptors, GABAC receptor modulators could be potential medications acting at low doses with fewer side effects.

Animals↗
PubMed2001

Role of nitric oxide synthases in the infarct size-reducing effect conferred by heat stress in isolated rat hearts.

Nitric oxide (NO) donors are known to induce both delayed cardioprotection and myocardial heat stress protein (HSP) expression. Moreover, heat stress (HS), which also protects myocardium against ischaemic damages, is associated with a NO release. Therefore, we have investigated the implication of NO in HS-induced resistance to myocardial infarction, in the isolated rat heart model. Rats were divided in six groups (n=10 in each group), subjected or not to heat stress (42 degrees C internal temperature, 15 min) and treated or not with nitro-L-arginine-methylester (L-NAME) a non-selective inhibitor of NO synthase isoforms, or L-N(6)-(1-imino-ethyl)lysine (L-NIL), a selective inhibitor of the inducible NO synthase. Twenty-four hours after heat stress, their hearts were isolated, retrogradely perfused, and subjected to a 30-min occlusion of the left coronary artery followed by 120 min of reperfusion. Infarct-to-risk ratio was significantly reduced in HS (18.7+/-1.6%) compared to Sham (33.0+/-1.7%) hearts. This effect was abolished in L-NAME-treated (41.7+/-3.1% in HS+L-NAME vs 35.2+/-3.0% in Sham+L-NAME ) and L-NIL-treated (36.1+/-3.4% in HS+L-NIL vs 42.1+/-4.6% in Sham+L-NIL) groups. Immunohistochemical analysis of myocardial HSP 27 and 72 showed an HS-induced increase of these proteins, which was not modified by L-NAME pretreatment. We conclude that NO synthases, and in particular the inducible isoform, appear to play a role in the heat stress-induced cardioprotection, independently of HSP 27 and 72 levels. Further investigations are required to elucidate the precise role of HSPs in this adaptive response.

Animals↗
PubMed2001

[Modification of some occlusion concepts in implant dentistry: thoughts inspired by clinical experience].

Implantology is nowadays a common tool in dentistry. While studying a case and selecting the future restoration, implants have to be considered when possible. Due to the functional differences between an implant and a natural tooth, the classical occlusion principles need to be considered. The prostheses have to be built according to the magnitude and direction of the forces that will be applied on the abutments. The prosthetic work and the occlusal equilibration are different in a patient with implants than in a patient with natural dentition. The occlusal concept will not be the same in the case of single implants surrounded by natural teeth, in the case of a mixed implant-tooth-supported fixed reconstruction and in the case of a full fixed bridge on implants. The purpose of this paper is to discuss the clinical consequences of these differences.

Biomechanical Phenomena↗
PubMed2000

Effect of okadaic acid, a protein phosphatase inhibitor, on heat stress-induced HSP72 synthesis and thermotolerance.

Heat stress proteins (HSPs), in particular HSP72, seem to play a major role in cell protection against lethal stresses such as hyperthermia or ischemia. HSP synthesis is negatively regulated by protein phosphatases, which are implicated in dephosphorylation processes. In the present study, we have investigated the effect of okadaic acid (OA, a protein phosphatase inhibitor) on heat stress-induced HSP72 synthesis and thermotolerance in smooth muscle cells (SMC). SMC were heat stressed (42 degrees C for 20 minutes) in the presence of 250 nM OA (HS+OA cells) or its vehicle (HS+V cells). Control (OA or V) cells were not heat stressed. HSP72 mRNA expression was determined 1, 1.5, 3, and 6 hours after heat stress by RT-PCR, and HSP72 synthesis was determined 6, 12, 24, 48, and 72 hours after heat stress by Western blotting. SMC survival of lethal hyperthermia (47 degrees C for 90 minutes) was assessed 6, 24, and 48 hours after heat stress by a tetrazolium assay. The maximal expression of HSP72 mRNA was markedly prolonged in HS+OA cells (until 6 hours after heat stress) compared to HS+V cells (1 hour after heat stress). The kinetics of HSP72 synthesis and thermotolerance of SMC were not different between HS+OA and HS+V cells. Baseline HSP72 mRNA and protein expression were similar in control V and OA cells. In conclusion, okadaic acid treatment of SMC potentiated HSP72 mRNA expression without affecting heat stress-induced HSP72 synthesis and thermotolerance.

Animals↗
PubMed2000

Nocturnal blood pressure and 24-hour pulse pressure are potent indicators of mortality in hemodialysis patients.

BACKGROUND: Cardiovascular (CV) complications are the leading cause of mortality in hemodialysis patients. The role of arterial hypertension on the prognosis of CV in hemodialysis patients is not as clear as in the general population. The purpose of this study was to investigate the prognostic role of ambulatory blood pressure (BP) on CV mortality in treated hypertensive hemodialysis patients. METHODS: Fifty-seven treated hypertensive hemodialysis patients (56.87 +/- 16.22 years, 30 men) were prospectively studied. All patients initially underwent an ambulatory BP monitoring between two dialysis sessions. The outcome event studied was CV death; kidney transplantation and deaths not related to CV disease were censored. RESULTS: The duration of follow-up was 34.4 +/- 20.39 months, during which 10 CV and 8 non-CV fatal events occurred. In the 10 patients who died from CV complications, age, previous CV events, ambulatory systolic BP, ambulatory pulse pressure (PP), and life-long smoking level were significantly higher, and the office diastolic BP was lower at the time of inclusion than in those who did not die from CV complications (N = 47). Based on Cox analysis and after adjustment for age, sex, and previous CV events, a low office diastolic BP [relative risk (RR) 0.49, 95% CI, 0.25 to 0.93, P = 0.03], an elevated 24-hour PP (RR 1.85, 95% CI, 1.28 to 2.65, P = 0.009), and an elevated nocturnal systolic BP (RR 1.41, 95% CI, 1.08 to 1.84, P = 0.01) were predictors of CV mortality (RR associated with a 10 mm Hg increase in BP and in PP). CONCLUSION: This study demonstrates that nocturnal BP and 24-hour PP are independent predictors of CV mortality in treated hypertensive hemodialysis patients. Randomized trials are needed to investigate whether nocturnal BP and 24-hour PP are superior to office BP as targets for antihypertensive therapy in this high-risk group.

Adult↗
PubMed2000

[Class II mechanics and overbite].

Class II mechanics are supposed to affect the vertical balance of the face when they are used in hyperdivergent patterns. We carried out a study about class II mechanics effects on 100 patients; 50 of them are hyperdivergent (GoGn/SN > or = 37), and 50 non-hyperdivergent. They all were treated with an Edgewise appliance without any high pull head gear. The authors showed that GoGn/SN angles and Occ/SN tend to be lessened in a skeletal open-bite population. Thus, Class II mechanics can be prescribed in any vertical facial pattern.

Cephalometry↗
PubMed1999

Long-term impact of superinfection by hepatitis G virus in hepatitis C virus-positive renal transplant patients.

BACKGROUND: The hepatitis G virus (HGV) has been recently cloned. Studies in immunocompetent patients have shown that HGV superinfection in hepatitis C virus (HCV)-positive patients does not affect (i) clinical presentation, HCV RNA level, or response to interferon-alpha therapy; or (ii) the histopathologic severity and characteristics of chronic hepatitis. No data are currently available on the impact of HGV infection on liver histology of renal transplant (RT) patients although the reported prevalence of serum HGV RNA in this population is high, ranging from 14% to 55%. PATIENTS AND METHODS: We determined the prevalence of HGV infection in 103 HCV-positive RT patients for whom HGV RNA was retrospectively determined by reverse transcription-polymerase chain reaction before, at the time of, and after transplantation (last follow-up). We evaluated the impact of HGV on liver function tests, liver histology (by means of the Knodell score), and renal parameters such as the prevalence of acute rejection and renal function. RESULTS: A total of 29 (28%) of the HCV-positive RT patients had a positive HGV RNA (group 1). The mean duration of HGV infection was at least 119+/-64 months (range: 18-240 months). Group 1 patients were compared to the 74 HGV RNA-negative/HCV-positive RT patients (group 2). Liver histology showed a significantly lower degree of fibrosis in group 1 (0.4+/-0.5) than in group 2 (1+/-1.2; P=0.02); two patients from group 2 but none from group 1 had overt cirrhosis. Conversely, the extent of hepatic inflammation and hepatocellular destruction was not statistically different between the two groups. The number of patients who experienced at least one acute rejection episode was significantly higher in group 1 (69%) than in group 2 (42%; P=0.01). However, the multivariate analysis did not identify the presence of HGV RNA at the time of renal transplantation as an independent factor of acute rejection; conversely, (i) the occurrence of cytomegalovirus infection or disease and (ii) the duration of HCV infection significantly increased the likelihood of having acute rejection. CONCLUSIONS: This study shows that: (i) HGV infection was often present when the patients seroconverted for HCV, (ii) HGV RNA-positive/HCV-positive RT patients experienced acute rejection more frequently than HGV RNA-negative/HCV-positive RT patients, and (iii) HGV infection seems to have no detrimental effect upon liver enzymes or liver histology in HCV-positive RT patients.

Adult↗