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A Besson

Publications and source records attributed to A Besson.

At least 37 records · Page 2Linked to original sources
PubMed1998

Reversal of learned helplessness by morphine in rats: involvement of a dopamine mediation.

The aim of this study was to examine the role of dopamine neurotransmission in the effects of morphine in the learned helplessness paradigm in rats, a generally recognized model of depression. In this model, rats first exposed to inescapable shocks (stressed rats) exhibited an escape deficit in a subsequent shuttle-box test performed 48 h later for 3 consecutive days. The numbers of escape failures and intertrial crossings (motor activity during each intertrial interval) were recorded. Morphine was injected twice daily for 5 days (6 mg/kg/day, s.c.), and haloperidol, a preferential D2-dopamine receptor antagonist, was injected i.p. 15 min before each shuttle-box session. At the highest dose tested (150 microg/kg) haloperidol mimicked the behavioral deficit produced by inescapable shocks. A 37.5 microg/kg dose of haloperidol, which was ineffective by itself, reversed the morphine-induced improvement of escape behavior in previously stressed rats and the morphine-induced increase in intertrial activity in both stressed and nonstressed animals. These results support roles (a) for a dysregulation of dopaminergic neuronal activity in the expression of escape deficit subsequent to an inescapable aversive situation, and (b) for a dopaminergic mediation in the effects of morphine in the learned helplessness paradigm.

Animals↗
PubMed1998

[Reproducibility of the radiographic analysis of dysplasia of the femoral trochlea. Intra- and interobserver analysis of 68 knees].

PURPOSE OF THE STUDY: The relation between patello-femoral instability and trochlear dysplasia was identified by Dejour. Trochlear dysplasia, diagnosed on knee lateral Xray when the trochlear groove crosses both femoral condyles (the so-called "crossing sign"), must be corrected to improve patello-femoral stability. However surgery should be related to the severity and the shape of trochlear dysplasia, underlining the importance of a reproducible classification. The aim of this study was to establish intra and inter-observer reliability of Dejour's radiographic criteria. MATERIAL: 68 preoperative exact knee profile radiographs were harvested from clinical records of 64 patients who underwent trochleoplasty because of patello-femoral instability and trochlear dysplasia. On these 68 views, the crossing sign was identified by the senior surgeon (F.G.) who performed or supervised surgery. METHOD: The 68 radiographs were examined independently by 7 observers (2 juniors, 5 seniors) in order to assess interobserver agreement. Two juniors repeated the observation to test intraobserver agreement. Reproducibility for categorical data (7 shapes of trochlea according to Dejour (3 for dysplasia)) was evaluated by Kappa statistics, and for numerical data (depth and anterior projection of the trochlear groove with respect to anterior femoral cortex) we used the interclass correlation analysis. RESULTS: Two out of the 7 observers rated all the 68 trochleas as dysplastics. The 5 others rated as normal 1 to 6 trochleas out of the 68. None of the 68 trochleas were recognized with the same shape by the 7 examiners. At best, 6 observers agreed on the same shape and for only 12 trochleas. Disagreement was mostly related to mistakes between type I and type II of dysplasia. For trochlear morphology interobserver agreement was slight (Kappa = 0.17) and intraobserver agreement was fair (Kappa = 0.3). The mean prominence of the trochlea was 3 +/- 2.1 mm [-6 to 10], and the mean trochlea depth was 1 +/- 1.9 mm [0 to 11]. These measurements were more reliable since the interclass correlation coefficients were respectively 0.62 and 0.38. The level of experience of the observers had no influence for categorical or numerical data. DISCUSSION: Our results indicated a low interobserver agreement for trochlear shape identification according to Dejour. The most reliable criteria was measurement of the trochlear prominence which was mostly pathological in our series. The "crossing sign" was reliable to diagnose dysplasia since the probability to rate as normal a true dysplastic trochlea was only 3.1 per cent. However, once the dysplasia diagnosed, this classification gave inconsistent results to select the trochlear shape, particularly for type II. To improve reproducibility we propose to diagnose a type II only when 5 millimeters separate the crossings between the medial and lateral condyles. CONCLUSION: We recommend to use anterior projection of the trochlear groove to rate trochlear dysplasia and to determine the adequate type of trochleoplasty: elevating of the lateral facet if non prominent or deepening of the groove when prominent.

Adolescent↗
PubMed1998

[Treatment of humeral fractures by Marchetti nailing. Apropos of 45 cases].

Between 1995 and 1997 we implanted 45 Marchetti nails. These nails were implanted for traumatic fractures in 39 patients, but also for pathologic fractures in 5 patients. Among these 39 patients, 7 were lost of view, the average age was 60 years. Among these 39 patients, 4 have got an other treatment before which failed. 10 fractures were placed D1, 8 fractures placed D2, 5 fractures placed D3, 16 fractures placed D4 according to the classification of Hackethal modified by De la Caffinière. The fracture type was classified according to A. O. classification: 7 A1, 11 A2, 7 A3, 2 B1, 6 B2, 1 B3, 4 C1, 1 C2. Among the 32 patients reviewed with an average of follow-up of 11 months, we have observed 5 very good results, 14 good results, 6 passable results and 3 bad results (classification of Stewart and Hundley). The average length of consolidation was 3 months. At follow-up the average elbow mobility was 129 degrees. Among the 3 bad results, there were 2 pseudarthrosis, in D4 zone. We have got 3 supracondylar fractures during the removal of the nail and 2 impactions of the metaphysis fracture. 5 patients had a nailing for pathologic fractures, one of them bilateral (4 women and one man, average age 65 years). Only two patients were reviewed, the fracture healed without any difference with the traumatic group. Contrary to other nailing, this materiel respects the rotator cuff. The global functional result was good.

Adolescent↗
PubMed1997

Comparison of amitriptyline metabolism in hepatocytes from streptozocin-induced diabetic rats and from non-diabetic rats.

Biotransformation of amitriptyline (AMI) was studied at different intervals in freshly isolated hepatocytes from healthy or streptozocin-induced diabetic rats in order to investigate the influence of the diabetic state. Levels of free and conjugated AMI, demethylated and hydroxylated metabolites, were assessed by HPLC analysis. In hepatocytes isolated from diabetic rats, AMI was less completely metabolized and the demethylation reaction became more important than in non-diabetic rat hepatocytes. Although the proportions of hydroxylated metabolites decreased in diabetic rats, it always remained predominant. Furthermore, glucuronidation of metabolites was greater, especially for (Z)-10-hydroxynortriptyline in diabetic animals.

Amitriptyline↗
PubMed1997

[Temporary antibiotic-loaded cemented prosthesis for two-stage septic hip arthroplasty].

PURPOSE OF THE STUDY: During the excision period of a two-stage revision arthroplasty, the hip has a low function and an unacceptable leg length discrepancy. The goal of this study was to expose technical details in order to perform a simple articulated cement spacer which could be implanted during this period to improve hip function, to authorize partial weight bearing and to avoid leg length discrepancy. MATERIAL: This method was applied in three two-stage procedures justified because of particular immunodeficiency conditions: a 43 years old man who had bone marrow allograft and immunosuppressive therapy because of leukemia suffering of subacute septic hip arthritis; a 58 years old man suffering of diabetes and active C-hepatitis who had a septic loosening of a total hip arthroplasty (THA); a 76 years old woman suffering of diabetes who had a third septic loosening of THA. METHOD: The prosthesis was made of antibiotic-impregnated cement according to organisms antibiotic resistance. The prosthetic junction between head and diaphysis was reinforced with a tibial plate. Prosthetic shape was identical to the one of femoral broaches inserted in the femur after prosthetic and cement removal. The broach size was chosen when mechanical stability in the femur was obtained, and avoided leg length discrepancy after trials with cups. The tibial plate was bent in order to reinforce the junction with regard to the shape of the determined broach. Two doses of antibiotic-impregnated cement were mixed and molded with hands, then the plate was incorporated at the appropriate location, finally the broach was applied on this composite and cement in excess was removed before polymerisation. For prosthetic head, two options were available: to mold the cephalic zone of the cement at the patient acetabulum diameter with a soft aluminium cup previously molded in the acetabulum; to mold the cement cephalic zone with a trial cup in order to obtain a 22 or 28 ball. For this last option, a third dose of antibiotic-impregnated cement was prepared and placed in the acetabulum, a trial femoral head was applied in it to mold the location for the 22 or 28 prosthetic head. Before insertion, a collar was applied on the stem to prevent migration. Active mobilization was encouraged, and partial weight-bearing authorized. RESULTS: The mean range of hip flexion during period was 60 degrees. The patients were discharged approximatively 12 days after the first stage. Two patients had effective painless partial weight-bearing. The second stage was performed six weeks later on the average. The second procedure was easier than the second stage of a conventional two-stage procedure because of: easy and low hemorrhagic dissection authorized by the prosthesis; low difficulties with soft tissue tension as the prosthesis prevents leg length discrepancy; preservation of the articular space which prevents soft tissue sacrifice during the second stage. CONCLUSION: This simple technique is effective to prevent complications related to the excision period of a two-stage hip revision arthroplasty. Likewise, the economical aspect (short delay of hospitalisation, quick functional recovery) should be considered when compared with the excision period of a conventional two-stage procedure.

Adult↗
PubMed1996

Effects of morphine, naloxone and their interaction in the learned-helplessness paradigm in rats.

The aim of this study was to investigate the possible involvement of the mu-opioid system on the learned-helplessness paradigm, an experimental model of depression, in rats. In this test, rats were first exposed to inescapable foot-shocks (IS); 48 h later, they were submitted to a daily shuttle-box session (30 trials) for 3 consecutive days. Avoidance responses, escape failures and animal activity during each intertrial interval were recorded. Twice daily injections of morphine (0.25-8 mg/kg per day, SC), a mu-opioid agonist, reduced the increased escape failures induced by IS, as did tricyclic antidepressants. Significantly higher intertrial activity was observed in rats treated with morphine (2-8 mg/kg per day) compared with their associated control groups. Naloxone (1 and 2 mg/kg, IP), a mu-opioid antagonist, injected 10 min before each shuttle-box session impaired escape behavior in non-stressed rats and worsened the escape deficit induced by IS. Morphine-induced improvement of escape behavior and increase in intertrial activity were clearly reversed by a low inactive dose of naloxone (0.5 mg/kg). These results suggest that mu-opioid receptor mediation is involved in the deleterious effects of uncontrollable stress.

Animals↗
PubMed1996

Plasma and brain pharmacokinetics of amitriptyline and its demethylated and hydroxylated metabolites after one and six half-life repeated administrations to rats.

The purposes of the present study were as follows: 1. After an acute intraperitoneal (IP) administration of amitriptyline (AMI) to male Sprague-Dawley rats we found that: (i) its absorption rate is rapid; (ii) its elimination half-life is much shorter than in humans; and (iii) its levels largely exceeded those of its metabolites. The most important metabolites being 10-hydroxynortriptyline and nortriptyline in plasma and brain, respectively. 2. After six (every half-life) repeated IP administrations: (i) AMI kinetic parameters were unchanged; and (ii) amounts of metabolites were significantly increased and the levels of AMI were lowered both in plasma and brain.

Amitriptyline↗
PubMed1996

Pharmacokinetics of amitriptyline and its demethylated and hydroxylated metabolites in streptozocin-induced diabetic rats.

Plasma and brain levels of amitriptyline (AMI), its demethylated and hydroxylated metabolites were determined after acute IP administration of AMI (20 mg/kg) in streptozocin-induced diabetic Sprague-Dawley rats. Results showed 1. in plasma: rapid AMI absorption, but slow elimination; the proportion of AMI similar to those of the rest of compounds; the proportion of its demethylated metabolite, nortriptyline, 1.8-fold higher than that of 10-hydroxy-nortriptyline. 2. in brain: the proportions of AMI and nortriptyline were 9.5- and 2.6-fold higher respectively, than those of whole hydroxylated metabolites, which represented 7.4% of the total amount.

Amitriptyline↗
PubMed1990

[Rupture of the diaphragm].

Incidence of chest and/or abdomen trauma has increased over the last three decades; it tends nowadays to stabilize. Among severe trunk injuries, diaphragm rupture--a life-threatening condition--occurs in 7% of cases. Overall mortality is around one third of casualties. Young (average 40 years of age) men (80% of cases) are especially exposed. Biomechanics, epidemiology, anatomy, physiopathology are reviewed. Comments are given upon clinical suspicion of the rupture as well as establishing its diagnosis, upon associated injuries, surgical indication for repair and treatment, with a special notice for resuscitative precautions. Numerous typical examples are illustrated.

Diagnosis, Differential↗