Specific Cues Can Improve Procedural Learning and Retention in Developmental Coordination Disorder and/or Developmental Dyslexia.

The present study investigates procedural learning of motor sequences in children with developmental coordination disorder (DCD) and/or developmental dyslexia (DD), typically-developing children (TD) and healthy adults with a special emphasis on (1) the role of the nature of stimuli and (2) the neuropsychological functions associated to final performance of the sequence. Seventy children and ten adults participated in this study and were separated in five experimental groups: TD, DCD, DD, and DCD + DD children and adults. Procedural learning was assessed with a serial reaction time task (SRTT) that required to tap on a specific key as accurately and quickly as possible when stimuli appeared on the screen. Three types of stimuli were proposed as cues: the classical version of the SRTT with 4 squares aligned horizontally on the screen, giving visuospatial cues (VS cues), and two modified versions, with 4 letters aligned horizontally on the screen (VS + L cues) and letters at the center of the screen (L cues). Reaction times (RT) during the repeated and random blocks allowed assessing three phases of learning: global learning, specific learning and retention of the sequence. Learning was considered as completed when RT evolved significantly in the three phases. Neuropsychological assessment involved, among other functions, memory and attentional functions. Our main result was that learning and retention were not influenced by the available cues in adults whereas learning improved with specific cues in children with or without neurodevelopmental disorders. More precisely, learning was not completed with L cues in children with neurodevelopmental disorders. For children with DD, learning was completed with the VS and VS + L cues whereas for children with DCD (with or without DD), learning was completed with combined VS + L cues. Comorbidity between DD and DCD had no more impact on procedural learning than DCD alone. These results suggest that learning depends on the nature of cues available during practice and that cues allowing learning and retention depend on the type of disorder. Moreover, selective attention was correlated with RT during retention, suggesting that this neuropsychological function is important for procedural learning whatever the available cues.

The treatment of idiopathic scoliosis in adolescents: rotation or in situ bending?

Rotation alone is not fully efficient in order to correct all types of scoliotic curvatures. We report a series of 30 cases instrumented with the EUROS spine system and analyse reductions obtained with in situ rotation or bending alone or with combined maneuvres. The average age of surgery is 17 years for this series composed of 24 female and 6 male patients. The average follow-up is 2.3 years. The curve patterns are displayed with 6 major thoracic, 5 genuine double major, 4 double major thoracic predominant, 6 double major lumbar predominant and 9 double thoracic curves. Combination of both reduction techniques is advisable and is to be made according to the type of curvature and its reducibility in situ bending is made easier with this system without lockers and by reduced diameter of the rod.

Pertussis toxin augments beta-adrenergic relaxation of muscarinic contraction in canine trachealis.

We studied the effect of pertussis toxin (PT) and partial muscarinic antagonism using pirenzepine (PIR) on beta-adrenergic relaxation of muscarinic contraction in 188 tracheal smooth muscle (TSM) preparations from 25 dogs in vitro. Strips of TSM were incubated for 4 h at 37 degrees C in Krebs-Henseleit (K-H) perfusate with or without 10 micrograms/ml of PT. In tissues contracted to target tension (TT; 50% of maximal response to 127 mM potassium-substituted K-H [KCl]) with acetylcholine (ACh), pretreatment with PT decreased the concentration of isoproterenol (ISO) causing 30% relaxation from TT (RC30) from 1.3 +/- 0.8 x 10(-7) M (control) to 2.8 +/- 0.7 x 10(-8) M (p = 0.013). Pretreatment with PT also augmented the maximal relaxation elicited by 10(-5) M ISO. In separate studies, strips of TSM were contracted with ACh; pretreatment with 10(-7) M PIR decreased the concentration of ISO causing 50% relaxation (RC50) from 3.4 +/- 0.6 x 10(-7) to 9.6 +/- 1.5 x 10(-8) M (p = 0.042). Pretreatment with PIR did not affect relaxation elicited by ISO for strips contracted equivalently with KCl. In addition, PIR increased both the potency and efficacy of ISO in relaxing muscarinic contraction in sham-incubated strips of TSM but had no effect after incubation with PT. Neither PT nor PIR affected beta-adrenergic relaxation of TSM contracted with KCl. Our data demonstrate that beta-adrenergic receptor relaxation of muscarinic contraction is augmented by (1) incubation with PT and (2) partial blockade of muscarinic receptors.

[Sequelae of osteoarthritis of the hip in growing children. Apropos of 72 cases]. / Les séquelles des ostéoarthrites de hanche en période de croissance. A propos de 72 cas.

The authors reviewed a series of 72 hips in 60 children with sequelae of septic arthritis of the hip to evaluate the long term evolution. The average follow up was 7 years 8 months (Range 1Y-17Y). 40 hips were operated and 32 were not. The results were analysed according to clinical and radiological criterions in an attempt to propose a guide for treatment. Sequelae might also occur after both initial treatment with open drainage or aspiration. The study of sequelae according to the factors of severity (organism, age when infected) showed that the evolution of these cases of arthritis cannot be forecast. The authors noticed that very severe roentgenographic lesions could be well tolerated clinically, at least on a medium term basis. They advise great care before operating on dislocated hips when they are clinically well tolerated. Finally the authors insist on 2 little known lesions: caput valgum and caput antetorsum.

Epithelial modulation of airway smooth muscle response to endothelin-1.

We investigated the role of epithelial modulation of contraction caused by endothelin-1 in airway smooth muscle in guinea pigs in situ. Airway responses were assessed isometrically as tracheal force and simultaneously as change in lung resistance. Intravenous administration of 10(-8) mol/kg endothelin-1 caused a biphasic response in tracheal active tension: initial relaxation (-0.82 +/- 0.22 g/cm after 30 s, p less than 0.05 versus baseline) followed by contraction (1.65 +/- 0.28 g/cm after 7 min, p less than 0.05 versus baseline). Endothelin-1 also elicited immediate bronchoconstriction; lung resistance increased from 0.148 +/- 0.030 to 0.992 +/- 0.274 cm H2O/L/s (p less than 0.005) after 10(-8) mol/kg endothelin-1 given intravenously. Active tension elicited by 10(-8) mol/kg endothelin-1 after removal of the epithelium from the tracheal segment (0.59 +/- 0.16 g/cm) was less than in segments with an intact epithelium (1.65 +/- 0.28 g/cm, p less than 0.01). Both tracheal contraction and bronchoconstriction were attenuated by pretreatment with indomethacin orally, BW 755C intravenously, or substitution of endothelin-C-terminal hexapeptide for endothelin-1. However, the initial tracheal relaxation response was similar after each intervention. These data suggest actions of endothelin-1 that have not been demonstrated previously: (1) endothelin-1 elicits a biphasic response in tracheal smooth muscle (an initial relaxation response elicited by the carboxy-terminal residues and a later contractile response that requires synthesis of a cyclooxygenase mediator) and (2) epithelium adjacent to the airway smooth muscle modulates contraction elicited by endothelin-1.

[Acute osteomyelitis of the ilium. A study of 2 cases with review of the literature]. / L'ostéomyélite aiguë de l'aile iliaque. Etude de 2 cas avec revue de la littérature.

The authors have made a review of the literature about two cases of osteomyelitis of the iliac ala. They insist on rarity of the disease and how often the right diagnosis may be delayed because of misleading clinical symptoms. Any tumefaction of the buttock associated with pelvic pain and with an infectious syndrome necessarily evoke an iliac osteomyelitis. The bone scan may be negative which need not exclude the possibility. The evolution may be the formation of intra or extra or sometimes simultaneous sub-periosteal abscesses which must be drained. This is the reason why the authors advise to verify systematically the other side of the ilium by its surgical trepanning in case of a sub-periosteal abscess.

New procedure to remove a centrally located bone bar.

A centrally located bone bar of the lower tibia was removed after epiphyseolysis with an Ilizarov device. The bone bridge attached to the metaphysis was easy to remove, and methylmethacrylate was used as an interpositional material. Varus deformity was corrected at the level of the epiphyseolysis. At the 2-year follow-up, there was evidence of further growth and correction of the varus was maintained.

[Role of acetabuloplasty in the treatment of residual cotyloid dysplasia before 4 years of age. Apropos of 14 cases followed over 5 years]. / La place de l'acétabuloplastie dans le traitement des dysplasies cotyloïdiennes résiduelles avant l'âge de 4 ans. A propos de 14 cas suivis plus de 5 ans.

Concerning 14 cases with a follow-up of over 5 years, the authors describe their acetabuloplasty technique which is applied to dysplastic sockets with normal cotyloid cavity anteversion, innominate osteotomy is reserved for cases in which this anteversion is excessive; results have been excellent for 11 cases with adequate lowering of the roof-edge of the cavity and improvement of the C and CE angles as well as satisfactory subsequent bone growth; the result was insufficient in 3 cases in which either the head of the femur was off-centre or deformed by osteochondritis. The age of the patients was between 16 and 37 months. No growth disorder caused by the operation has been observed. Three failures may be related to pre-existing abnormalities in the growing areas of the acetabulum or to ischaemic troubles in the femoral head.

Is the Cotrel-Dubousset really universal in the surgical treatment of idiopathic scoliosis?

We reviewed the results of 22 cases of Cotrel-Dubousset (C-D) instrumentation, 16 cases of anterior approach, and 200 cases of posterior approach by Harrington instrumentation and modifications of Harrington procedure. Posterior spinal fusion and instrumentation by C-D gives better correction and stabilization in thoracic and balanced double major curves. We no longer use the Harrington procedure and its modification. In lumbar and short thoracolumbar curves, VDS is still preferred. In some double major curves combined procedures, VDS and C-D are used to obtain more correction with a shorter fusion area.

[The treatment of old dislocations of the radial head in children by osteotomy of the upper end of the ulna. Apropos of 15 cases]. / Le traitement des luxations anciennes de la tête radiale chez l'enfant par l'ostéotomie haute du cubitus. A propos de 15 cas.

Fifteen old dislocations of the radial head in children were treated by open reduction combined with a high osteotomy of the ulna and a reconstruction of the annular ligament. This method, described by the authors in 1978, was used in nine post-traumatic, three congenital, two paralytic and one dislocation associated with multiple exostoses. Twelve children were reviewed with a follow-up of two to 11 years. Nine radial heads remained stable and well reduced. The three congenital dislocations recurred. Eight elbows showed normal alignment and the other four were only improved. Ten elbows had normal movement or better movement than before the operation. Eleven children used their elbow normally or better than before. In all, 14 children were improved, and only one elbow had unaltered function. The results obtained in congenital dislocations should be able to be improved by a number of technical precautions.

Endogenous modulation of alpha-adrenergic contraction in canine tracheal muscle.

We studied the effect of passive stretch on the contraction of canine tracheal smooth muscle (TSM) to alpha-adrenergic agonists and acetylcholine (ACh) in 211 epithelium-free TSM strips from 42 dogs in vitro. Passive stretch at a resting tension of 100 g/cm2 caused a time-dependent decrease in the contractile response to alpha-adrenergic agonists after beta-adrenergic blockade with propranolol. Initial contraction elicited by 10(-3) M phenylephrine (PE) and clonidine (CLO) decreased at 2 h by 31 and 100%, respectively. Decrease in alpha-adrenergic contractility did not result from tachyphylaxis; no contraction was elicited by PE or CLO given for the first time after 4-h passive stretch at 100 g/cm2. The TSM response to ACh was unchanged over the same time in the same strips. When TSM strips were incubated at zero resting tension for 6 h, some attenuation of the alpha-adrenergic contractile still occurred but was not substantial. Similarly, when strips were incubated with 10(-6) M indomethacin (INDO) or 10(-5) M mefenamic acid (MEF) at 100 g/cm2 resting tension, time-dependent attenuation of the response to PE and CLO was reduced for at least 6 h, and initial contraction elicited by PE was augmented. Response of TSM to ACh was not affected by prostaglandin synthetase inhibition with INDO. We conclude that passive stretch of canine TSM in vitro leads to decreased responsiveness to alpha-adrenergic stimulation that can be prevented with INDO or MEF. These data are consistent with the synthesis of an inhibitory eicosanoid in epithelium-free canine TSM that may be activated by mechanical deformation of the muscle.

Augmentation of respiratory mast cell secretion of histamine caused by vagus nerve stimulation during antigen challenge.

We studied the effect of vagus nerve stimulation on the mast cell secretion of histamine after intraarterial (i.a.) administration of Ascaris suum antigen (AA) into the bronchial circulation of 10 randomly selected, natively allergic dogs in vivo. Respiratory mast cell response was measured as the arteriovenous difference (AVd) in histamine concentration across the bronchus. Plasma histamine concentration was determined simultaneously from right atrium, right ventricle, and femoral artery 60 and 15 sec before and 15, 30, 45, 60, 75, and 90 sec after i.a. injection of sham (Kreb-Henseleit) diluent, 1:100, and 1:30 concentrations of AA. The mean AVd in plasma histamine for five parasympathetically blocked animals (neural blockade with hexamethonium and beta-adrenergic blockade with propranolol) was 1.28 +/- 0.61 ng/ml (sham), 5.16 +/- 19.7 ng/ml (1:100 AA), and 36.6 +/- 11.1 ng/ml (1:30 AA). Substantial augmentation was obtained when AA was administered during parasympathetic stimulation in five other animals (beta-adrenergic blockade, no neural blockade), which was caused by continuous bilateral electrical stimulation of the vagus nerves. A mean AVd in plasma histamine of 110 +/- 27.6 ng/ml was obtained after 1:100 AA (p less than 0.001 vs parasympathetic blockade) and 166 +/- 32.4 ng/ml for 1:30 AA (p less than 0.001 vs parasympathetic blockade). Parasympathetic stimulation alone did not cause secretion of histamine. In contrast to the AVd response, parasympathetic stimulation did not augment nonrespiratory mast cell secretion after AA challenge. We conclude that vagus nerve stimulation augments secretion of histamine from respiratory mast cells during antigen challenge. We demonstrate that parasympathetic stimulation may potentiate the response to antigen challenge in central airways through augmented mast cell secretion of mediator.

Physiological antagonism caused by adrenergic stimulation of canine tracheal muscle.

We studied the simultaneous alpha- and beta-adrenergic response characteristics of canine tracheal smooth muscle in 398 strips from 67 dogs in vitro. Experiments were performed to determine the effects of beta-adrenergic blockade on the expression of the alpha-adrenoceptor contractile responses elicited by norepinephrine (NE), phenylephrine (PE), and clonidine (CLO). Maximal active tension caused by NE increased from 39.1 +/- 27.0 to 241 +/- 75.0 g/cm2 as the concentration of propranolol (PROP) was increased from 10(-6) to 10(-4) M. Augmentation of tracheal smooth muscle contraction caused by PE and CLO was also observed with progressive beta-adrenoceptor blockade; contraction to NE, PE, and CLO was blocked selectively with 3 X 10(-5) M phentolamine (PA) and phenoxybenzamine (PBZ). The beta-adrenergic relaxing properties of the same three agonists were also studied. After alpha-adrenergic blockade with PA or PBZ, all three agonists caused relaxation (NE greater than CLO greater than PE) of methacholine-induced contraction of tracheal smooth muscle that was reversed selectively with PROP. We demonstrate that NE, PE, and CLO cause simultaneous stimulation of both the alpha- and beta-adrenergic receptors in tracheal smooth muscle; the net response elicited is the result of adrenergic physiological antagonism and depends on the relative degree of alpha- and/or beta-adrenoceptor blockade.

[Surgical treatment of congenital dislocation of the hip in older children; analysis of the results. Apropos of 46 cases]. / Traitement chirurgical de la luxation congénitale de hanche du grand enfant; analyse des résultats. A propos de 46 cas.

The results of surgical treatment of 46 congenital dislocations of the hip in children older than 4 years are analysed. Several techniques were used; progressive traction for a short time, stabilisation by plaster cast immobilisation or surgical reduction, pelvic osteotomy with or without combined femoral rotation osteotomy with shortening. Apart from other means of assessment, 3 radiological signs were used to determine the results - sphericity of the femoral head, coverage of the femoral head and centering of the femoral head. A new classification is proposed by the authors. Only 25 p. 100 of the results were excellent or good. The other hips had at least one radiological anomaly and 17.5 p. 100 of the hips had a non-spherical head. Cases with poor coverage of the femoral head did well when this was the only defect because this anomaly was easily corrected. In contrast, excentration of the femoral head was poorly tolerated in the long term. The degree and direction of excentration had to be assessed in the frontal plane.

Sympathetic modulation of biochemical and physiological response to immune degranulation in canine bronchial airways in vivo.

The effect of sympathetic stimulation on bronchial smooth muscle contractile response after mast cell degranulation with Ascaris suum antigen was studied in 36 natively allergic dogs in situ. Bronchial smooth muscle response was measured isometrically in a single right middle lobe bronchus. A dose of antigen causing maximal release of mediator was administered to the bronchus through the bronchial arterial circulation. Serial plasma histamine concentrations were determined at 15-s intervals after intra-arterial (i.a.) administration of antigen. Samples of blood were obtained simultaneously from right heart and femoral artery, and arteriovenous difference (AVd) in histamine concentration across the bronchus was determined during mast cell degranulation. In nine dogs showing bronchial mast cell degranulation to antigen challenge, bronchial smooth muscle contraction was 22.3 +/- 2.95 g and the mean AVd in histamine concentration across the bronchus was 188 +/- 41.5 ng/ml. Six other dogs having muscarinic blockade with 0.75-1.0 mg/kg intravenous atropine were given i.a. antigen after 1 min of steady-state sympathetic stimulation with intravenous 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP). Sympathetic stimulation during Ascaris suum antigen challenge caused complete inhibition of bronchial smooth muscle contractile response to i.a. antigen (P less than 0.001), and a significant AVd in histamine concentration across the bronchus (9.8 +/- 16.0 ng/ml; P less than 0.01 vs. control) was not detected. Peak plasma histamine concentration in control dogs was 1,138 +/- 237 ng/ml vs. 310 +/- 135 ng/ml in animals receiving sympathetic stimulation (P less than 0.01). In four dogs undergoing systemic anaphylaxis to i.v. antigen, subsequent sympathetic stimulation with i.v. DMPP reduced bronchomotor tone to approximately 70% of base-line control. Exogenously induced sympathetic stimulation can substantially inhibit systemic mast cell degranulation to Ascaris suum antigen in allergic dogs. Maximal stimulation of the sympathetic nervous system causes substantial inhibition of respiratory mast cell secretion of histamine and bronchial smooth muscle contraction to circulating mediator.

Augmentation of parasympathetic contraction in tracheal and bronchial airways by PGF2 alpha in situ.

We studied the effect of exogenous prostaglandin F2 alpha (PGF2 alpha) on airway smooth muscle contraction caused by parasympathetic stimulation in 22 mongrel dogs in situ. Voltage (0-30 V, constant 20 Hz) and frequency-response (0-25 Hz, 25 V) curves were generated by stimulating the cut ends of both cervical vagus nerves. Airway response was measured isometrically as active tension (AT) in a segment of cervical trachea and as change in airway resistance (RL) and dynamic compliance (Cdyn) in bronchial airways. One hour after 5 mg/kg iv indomethacin, a cumulative frequency-response curve was generated in nine animals by electrical stimulation of the vagus nerves at 15-s intervals. Reproducibility was demonstrated by generating a second curve 7 min later. A third frequency-response curve was generated during active contraction of the airway caused by continuous intravenous infusion of 10 micrograms X kg-1 X min-1PPGF2 alpha. Additional frequency-response studies were generated 15 and 30 min after PGF2 alpha, when airway contractile response (delta RL = +2.8 +/- 0.65 cmH2O X 1(-1) X s; delta Cdyn = -0.0259 +/- 0.007 1/cmH2O) returned to base line. Substantial augmentation of AT, RL, and Cdyn responses was demonstrated in every animal studied (P less than 0.01 for all points greater than 8 Hz) 15 min after PGF2 alpha. At 30 min, response did not differ from initial base-line control. In four animals receiving sham infusion, all frequency-response curves were identical. We demonstrate that PGF2 alpha augments the response to vagus nerve stimulation in tracheal and bronchial airways. Augmentation does not depend on PGF2 alpha-induced active tone.