Mandibular distraction osteogenesis in Pierre Robin sequence: application of a new internal single-stage resorbable device

Pierre Robin sequence may result in physiologically significant obstructive apnea in the neonatal and infant period. This may be life threatening and is most often treated by tracheostomy. To avoid tracheostomy or allow for early decannulation in severely affected infants and children, the authors have developed a new class of neonatal and infant mandibular bone distraction devices. These devices require a single operative procedure for placement and no operative removal is necessary. Fifteen infants (aged 7 days to 11 months; mean age, 3 months) and five children (aged 2 to 8 years; mean age, 5.5 years), 10 boys and 10 girls, with severe obstructive apnea and Pierre Robin sequence were treated with the mandibular infant devices over a 24-month period. Tracheostomy was avoided in 14 patients, whereas five of six patients who had previous tracheostomy were decannulated after mandibular distraction. The final tracheostomy status in one patient will be determined after surgery for gastroesophageal reflux. There were no major complications and no structural device failures.     

Performance of noncountermovement jump with both knee and hip joints fully extended

The relationships between neuromuscular performance and biomechanical variables were studied in maximum vertical jumps to examine the factors influencing the performance of a noncountermovement jump. Keeping their knee and hip joint fully extended, five healthy subjects performed four kinds of noncountermovement jumps and one countermovement jump, during which ankle joint angle, platform force, and surface electromyograms of a triceps surae muscle were recorded. In the four noncountermovement jumps, the magnitude of activation and force at the onset of a shortening contraction of the triceps surae muscle were controlled at four different levels. Performance parameters of the noncountermovement jumps, maximum angular velocity of the ankle angle and flight time, correlated with the platform force at the onset of the plantar flexion. Furthermore the integrated electromyograms of the triceps surae muscle before the plantar flexion were correlated with the maximum angular velocity of the ankle angle and the force at the plantar flexion onset. The findings suggest that the efficient utilization of the muscle characteristic contributes to an enhancement of the noncountermovement jump.     

To distract or not to distract: an algorithm for airway management in isolated Pierre Robin sequence

Approaches advocated for treatment of airway obstruction among neonates with Pierre Robin sequence include positioning, tongue-lip adhesion, mandibular distraction, and tracheostomy, with no established guidelines regarding which modality is appropriate for a specific patient. This report proposes an algorithm for the management of neonatal upper airway obstruction among patients with isolated Pierre Robin sequence. Data for 21 patients with isolated Pierre Robin sequence who were treated by one surgeon during a 9-year period were reviewed. Eighteen patients presented during the first 1 week of life and three patients presented late, between 12 and 33 months of age. Follow-up periods ranged from 9 to 70 months (median, 33 months). Successful airway management was achieved with positioning alone for 10 patients, with tongue-lip adhesion for seven of nine patients, with tracheostomy for two patients, and with mandibular distraction for three patients. Changes in the maxillary-mandibular discrepancy were significant with natural mandibular growth during the first 1 year of life (p < 0.0001). Oromotor studies performed 3 months or more after tongue-lip adhesion reversal (n = 9) demonstrated no appreciable deficits in tongue function, relative to other children with cleft lips/palates. A multidisciplinary team should evaluate all patients with isolated Pierre Robin sequence, to fully assess the maxillary-mandibular relationship, anatomically define the site of airway obstruction, and identify feeding difficulties. Patients should be evaluated for episodes of desaturation occurring spontaneously, during feeding, or during sleeping. Patients with desaturation should be further evaluated with double endoscopy (nasoendoscopy and bronchoscopy). If the airway obstruction is localized to the tongue base alone and cannot be controlled with positioning, then tongue-lip adhesion is the initial treatment of choice, because such patients demonstrate significant mandibular growth during the first 1 year of life. Mandibular distraction among neonates is reserved for failures of tongue-lip adhesion in which isolated tongue-base airway obstruction is documented. Neither of the patients who experienced failure of tongue-lip adhesion in this series would have been a candidate for distraction with the algorithm presented. Avoiding routine neonatal distraction serves to avoid facial scarring, nerve and tooth bud injury, and potential disturbances of intrinsic mandibular growth. Patients with persistent respiratory difficulties beyond age 9 months require reevaluation for multiple sites of airway obstruction. Mandibular distraction may be one of several modalities required to avoid tracheostomy for such patients.     

Tapping into the endocannabinoid system to ameliorate acute inflammatory flares and associated pain in mouse knee joints

Introduction

During the progression of rheumatoid arthritis (RA), there are frequent but intermittent flares in which the joint becomes acutely inflamed and painful. Although a number of drug therapies are currently used to treat RA, their effectiveness is variable and side effects are common. Endocannabinoids have the potential to ameliorate joint pain and inflammation, but these beneficial effects are limited by their rapid degradation. One enzyme responsible for endocannabinoid breakdown is fatty acid amide hydrolase (FAAH). The present study examined whether URB597, a potent and selective FAAH inhibitor, could alter inflammation and pain in a mouse model of acute synovitis.

Methods

Acute joint inflammation was induced in male C57BL/6 mice by intra-articular injection of 2% kaolin/2% carrageenan. After 24 hr, articular leukocyte kinetics and blood flow were used as measures of inflammation, while hindlimb weight bearing and von Frey hair algesiometry were used as measures of joint pain. The effects of local URB597 administration were then determined in the presence or absence of either the cannabinoid (CB)1 receptor antagonist AM251, or the CB2 receptor antagonist AM630.

Results

URB597 decreased leukocyte rolling and adhesion, as well as inflammation-induced hyperaemia. However, these effects were only apparent at low doses and the effects of URB597 were absent at higher doses. In addition to the anti-inflammatory effects of URB597, fatty acid amide hydrolase (FAAH) inhibition improved both hindlimb weight bearing and von Frey hair withdrawal thresholds. The anti-inflammatory effects of URB597 on leukocyte rolling and vascular perfusion were blocked by both CB1 and CB2 antagonism, while the effect on leukocyte adherence was independent of cannabinoid receptor activation. The analgesic effects of URB597 were CB1 mediated.

Conclusions

These results suggest that the endocannabinoid system of the joint can be harnessed to decrease acute inflammatory reactions and the concomitant pain associated with these episodes.     

Innovative surgical approach for the Pierre Robin anomalad: subperiosteal release of the floor of the mouth musculature

The Pierre Robin anomalad presenting with severe respiratory distress is a difficult situation still associated with a significant mortality rate. A surgical approach based on a new idea is described. The concept is that the musculature of the floor of the mouth is under increased tension and pushes the tongue upward and backward with secondary respiratory obstruction. The surgical approach consists of a subperiosteal release of the musculature of the floor of the mouth through a 2-cm submental incision. So far this procedure has been used in four patients with severe obstruction, and marked improvement has occurred postoperatively in all cases. This surgical technique is simple and is associated with little morbidity. It should lessen the need for tracheostomy, which carries a greater morbidity, especially in newborns. We think that this new surgical approach can significantly improve the outcome of the severe form of Pierre Robin anomalad.     

Preparation of whole rabbit knee joints for microscopic examination

A paraffin embedding method to prepare whole rabbit knee joints for histological examination is described. This method provides good quality microscopic sections thin enough for the study of cellular detail and does not require prolonged processing. When examining pathologic changes in experimental arthritis, it is advantageous to be able to examine the intact joint with the structural relations of the joint components preserved. Sections of the whole joint provide numerous areas where bone, cartilage and synovium are contiguous for examination. Having obtained poor results using methods recommended for small bony specimens, we modified several existing procedures to obtain a reliable method for preparing excellent microscopic sections of the whole rabbit knee joint.     

Changes in knee function associated with treadmill ambulation

A comparison of level walking, on a walkway and on a treadmill, was performed using ten normal subjects. Motion about the knee was measured using a triaxial electrogoniometer, and foot-floor contact patterns were recorded by means of four foot switches attached to the sole of each shoe. On the walkway, the data were collected with the subject moving at a comfortable walking speed. The treadmill was then set at the average velocity obtained on the walkway. Knee joint rotation in the coronal and transverse planes did not change significantly between the walkway and the treadmill. In the sagittal plane, significant differences were found for total motion (p less than 0.01), swing phase motion (p less than 0.01), knee position at heel strike (p less than 0.05), and maximum swing phase extension (p less than 0.01). A comparison of the foot-floor contact patterns between walkway and treadmill ambulation revealed reduced heel contact time, with an increase in toe contact while on the treadmill. It was concluded that sagittal plane knee kinematics during level treadmill walking differ significantly from level overground walking.     

Gigantism associated with McCune-Albright's syndrome

The case of a 16 year-old boy with McCune-Albright's syndrome which is rarely accompanied by gigantism was studied endocrinologically. The stimulation of growth hormone (GH) release by hypoglycemia, the decline of elevated GH by hyperglycemia and a little lower somatostatin like immunoreactivity (SLI) may support abnormalities of hypothalamic function, but the existence of pituitary microadenoma cannot be ruled out because of the paradoxical suppression of GH release by oral administration of bromocriptine (CB-154) and L-DOPA and the stimulation of GH release by intravenous administration of TRH.     

Abrogation of alpha-adrenergic vasoactivity in chronically inflamed rat knee joints

It has previously been shown that chronic inflammation causes a reduction in sympathetic nerve-mediated vasoconstriction in rat knees. To determine whether this phenomenon is due to an alteration in smooth muscle adrenoceptor function, the present study compared the alpha-adrenoceptor profile of blood vessels supplying the anteromedial capsule of normal and chronically inflamed rat knee joints. While the rats were under urethan anesthesia, the alpha(1)-adrenoceptor agonists methoxamine and phenylephrine and the alpha(2)-adrenoceptor agonist clonidine (0.1-ml bolus; dose range 10(-12)-10(-7) mol) were applied to exposed normal rat knees, resulting in a dose-dependent fall in capsular perfusion. Comparison of drug potencies indicated that alpha(2)-adrenergic effects > alpha(1)-vasoactivity. One week after intra-articular injection of Freund's complete adjuvant to induce chronic joint inflammation, the vasoconstrictor effects of methoxamine, phenylephrine, and clonidine were all significantly attenuated compared with normal controls. These findings show that the preponderance of sympathetic adrenergic vasoconstriction in the anteromedial capsule of the rat is carried out by postjunctional alpha(2)-adrenoceptors. Chronic joint inflammation compromises alpha(1)- and alpha(2)-adrenoceptor function, and this change in alpha-adrenergic responsiveness may help explain the perfusion changes commonly associated with inflammatory arthritis.     

Baller-Gerold syndrome associated with dextrocardia

Baller-Gerold Syndrome (BGS) is a rare autosomal recessive disorder that is apparent at birth. The disorder is characterized by distinctive malformations of the skull and facial area and bones of the forearms and hands. We report a 4 year old boy in whom the clinical features of craniosynostosis and bilateral absent thumbs and radii led to a diagnosis of Baller-Gerold syndrome. Physical examination revealed that the heart was localized to the right side. Echocardiography confirmed dextrocardia. Dextrocardia has not previously been reported with Baller-Gerold syndrome. To the best of our knowledge, this is the first reported case of Baller-Gerold syndrome associated with dextrocardia.     

A case of Melkersson-Rosenthal syndrome associated with Ehlers-Danlos syndrome

Melkersson-Rosenthal syndrome (MRS) is characterized by the triad of recurrent facial palsy, lingua plicata, and facial edema. Herein, we report a case of MRS associated with Ehlers-Danlos syndrome due to rare presentation. To the best of our knowledge only one case of MRS associated with Ehlers-Danlos syndrome has been reported in the literature until now.