Biomedical subjects
Publications and source records attributed to A M Capelli.
Pfizer is developing the atropoisomeric quinoxalinediones, UK-315716 and UK-240255, from a series of NMDA/glycine antagonists for the potential treatment of stroke. Both are compounds are undergoing clinical trials. UK-315716 has improved aqueous solubility and in vivo efficacy over UK-240455, and a lower projected clinical dose of 200 mg compared to 500 mg with UK-240455.
A series of 5-phenyl-3-ureidobenzodiazepine-2,4-diones was synthesized and evaluated as cholecystokinin-B (CCK-B) receptor antagonists. Structure-activity relationship (SAR) studies revealed the importance of the N-1 substituent for potent and selective CCK-B affinity. Addition of substituents at the urea side chain provided in some cases more potent compounds. Moreover the introduction of bulky substituents such as adamantylmethyl at N-1 and resolution of the racemic ureas resulted in our lead compound GV150013.
A novel series of indole-2-carboxylate analogues of GV 150526 (1) in which the terminal phenyl ring belonging to the side chain present in the position C-3 has been replaced with a bridged cycloalkyl group was synthesized and evaluated for its pharmacological profile. Modelling studies on this class of novel glycine antagonist allowed us to identify an asymmetric lipophilic pocket present in the "North-Eastern" region of the pharmacophoric model of the glycine binding site associated to the NMDA receptor. Among the derivatives prepared, 3-[2-(1-adamantylaminocarbonyl)ethenyl]-4,6-dichloroindole-2 -carboxylic acid 6b and 3-[2-(norbornylaminocarbonyl)ethenyl]-4,6-dichloroindole-2-c arboxylic acid 6l were found to be antagonists acting at the strychnine-insensitive glycine binding site, showing nanomolar affinity for the glycine binding site (Ki = 63 and 19 nM, respectively), coupled with high glutamate receptor selectivity (IC50 > 10(-5) M at the NMDA, AMPA, KA binding sites) and high in vivo potency after systemic administration by inhibition of convulsion induced by NMDA in mice.
A series of indole-2-carboxylates bearing suitable chains at the C-3 position of the indole nucleus was synthesized and evaluated in terms of in vitro affinity using [3H]glycine binding assay and in vivo potency by inhibition of convulsions induced by N-methyl-D-aspartate (NMDA) in mice. 3-[2-[(Phenylamino)carbonyl]ethenyl]-4,6-dichloroindole-2-carboxyl ic acid (8) was an antagonist at the strychnine-insensitive glycine binding site (noncompetitive inhibition of the binding of [3H]TCP, pA2 = 8.1) displaying nanomolar affinity for the glycine binding site (pKi = 8.5), coupled with high glutamate receptor selectivity (> 1000-fold relative to the affinity at the NMDA, AMPA, and kainate binding sites). This indole derivative inhibited convulsions induced by NMDA in mice, when administered by both iv and po routes (ED50 = 0.06 and 6 mg/kg, respectively). The effect of the substituents on the terminal phenyl ring of the C-3 side chain was investigated. QSAR analysis suggested that the pKi value decreases with lipophilicity and steric bulk of substituents and increases with the electron donor resonance effect of the groups present in the para position of the terminal phenyl ring. According to these results the terminal phenyl ring of the C-3 side chain should lie in a nonhydrophobic pocket of limited size, refining the proposed pharmacophore model of the glycine binding site associated with the NMDA receptor.
Twenty-five patients, 11 to 19 years in age, were treated with hip arthrodesis for an incapacitating painful and stiff hip. Clinical diagnoses included avascular necrosis (AVN) associated with slipped capital femoral epiphysis (SCFE) (7 patients), posttraumatic AVN (6), septic arthritis (4), complication of treatment of developmental dysplasia of the hip (DDH) (4), pathologic fracture of femoral neck through bone cyst with resulting AVN (2), Perthes disease (1), and idiopathic chondrolysis (1). Preoperative motion was minimal or absent in 13 patients, limited in 12, and very painful in 23 patients. A two-incision surgical approach was utilized, providing for an intra-articular fusion technique and internal fixation with precise positioning. The surgical technique described avoids any dissection of the hip abductor musculature or a deforming osteotomy of the proximal femur. Twelve complications occurred in 10 patients, 9 of which required additional operative treatment. At an average postoperative follow-up of 6 years, 10 months, the overall activity level was greatly increased over the preoperative activity level secondary to the relief of pain. Hip arthrodesis is the acceptable salvage procedure for the otherwise healthy, active adolescent or young adult with unilateral hip disease characterized by incapacitating pain and/or an unacceptable fixed position.
Seven children (3-10 years of age) were treated for a type III supracondylar fracture of the humerus. All fractures were reduced and pinned. Closed reduction was performed in four patients; three required open reduction. Before reduction six of the seven patients did not have a distal palpable pulse in the involved forearm. After reduction of the fractures all patients had a pulseless arm and a seemingly viable hand. Doppler pulses were absent or greatly diminished compared with the normal side in all involved extremities. Six patients underwent immediate antecubital fossa exploration of the brachial artery without arteriogram; one patient, referred to us from another facility, underwent angiography followed by immediate exploration. In three patients the brachial artery was directly damaged or transected and was repaired via saphenous vein graft, with reestablishment of distal pulses in each case. In the other four patients the brachial artery was kinked or entrapped at the fracture site, necessitating microdissection to mobilize the vessel and reestablish pulses in each case. At an average follow-up of 30 months, all seven patients had normal circulatory status, including a radial pulse. All fractures had healed, and all extremities had a normal carrying angle and normal elbow motion. Immediate exploration of the antecubital fossa should be considered if an extremity remains pulseless (to palpation and Doppler) after reduction and stabilization of significantly displaced supracondylar fractures of the humerus.
Forty-four patients (fifty-two hips) who had static encephalopathy and acetabular dysplasia were managed with a Pemberton osteotomy as part of a comprehensive operative approach. Thirty-three patients had quadriplegia and were unable to walk; the remaining eleven patients had diplegia and could walk. The age at the time of the operation ranged from four years and five months to sixteen years and five months, as an open triradiate cartilage is a prerequisite for the Pemberton procedure. Concomitant operative procedures included a varus rotational osteotomy in fifty of the involved hips, a soft-tissue release in thirty-seven hips, and an open reduction in thirteen hips. The mean center-edge angle preoperatively was -11 degrees (range, -80 to 17 degrees), which improved to a mean of 27 degrees (range, 5 to 62 degrees) at the time of the latest follow-up. The mean duration of follow-up was four years (range, two years to eight years and eight months). At the time of writing, none of the hips had redislocated but one hip had subluxated. Eight of the hips had been painful preoperatively, but none of these was painful at the time of the most recent follow-up. One patient who had not had pain in the hip preoperatively had pain at the time of the follow-up evaluation. There were no complications attributable to posterior uncovering of the hip. The age of the patient at the time of the operation had no discernible effect on the result.
The acetabular response to proximal femoral varus rotational osteotomy was studied radiographically in twenty-eight patients who had had thirty-three congenitally dislocated hips. All of the patients had previously been managed with open or closed reduction followed by use of a spica cast and had worn an abduction orthosis for at least one year after the reduction. The indications for the femoral osteotomy were a persistently increased acetabular index or subluxation, or both. The average of the patients at the time of the femoral osteotomy was twenty-five months. The average preoperative acetabular index was 32 degrees. At an average of seven years after the osteotomy, the acetabular index had improved to an average of 16 degrees. Four hips had had one subsequent procedure for persistent acetabular dysplasia. Despite a failure of the acetabulum to respond to use of an abduction splint, the proximal femoral varus rotational osteotomy stimulated improvement in the acetabular index to within normal limits in twenty-nine of the thirty-three hips.
A roentgenographic review was made of 109 patients with unilateral Legg-Perthes disease, all of whom had experienced onset of symptoms prior to their sixth birthday. Roentgenograms taken at the time of healing and at final follow-up were grouped according to Catterall classification and modified Mose rating. The parameters measured were epiphyseal index, center-edge angle, extrusion index, epiphyseal quotient, and center-edge quotient. Average age at final follow-up was 12 years. A change in Mose rating between assessments at healing and final follow-up occurred in 16% of patients, with most of them showing improvement, supporting the concept that femoral heads in young children have the capacity to remodel. However, 24% of patients with Catterall III and IV disease had a poor result at final follow-up. Despite early onset of Legg-Perthes disease, patients with involvement of greater than half the femoral head are at risk for poor roentgenographic result.
Five cases of congenital pseudarthrosis of the clavicle were treated with open reduction and fixation with appropriate-sized contoured plates and screws. Iliac bone grafts were used to bridge the gap in four patients; local bone graft was used in the fifth patient. Consolidation was noted an average of 3 months postoperatively in all five cases. The plate and screws were removed in all patients at an average of 16 months postoperatively. Average length of follow-up for the five patients is 4 years. Roentgenograms demonstrate that the clavicle has continued to grow normally. All five patients have pain-free full range of motion and are engaged in unrestricted activities.
Seven children, between ten and thirteen years old, had elevation of the medial plateau of the tibia for correction of severe varus deformity secondary to Blount disease. The deformity was severe (grade V or VI according to the system of Langenskiöld and Riska) in all patients; the average preoperative varus deformity, determined by the angle formed by the femoral shaft and the tibial shaft, was 25 degrees. The goal of the operation was restoration of a more normal configuration of the articular surface of the proximal end of the tibia. This was accomplished by direct elevation of the depressed medial tibial plateau. All patients had an osteotomy to correct the alignment of the tibia. The osteotomy was performed concomitant with the elevation of the plateau in three patients, before the elevation in three, and after the elevation in one patient. Four patients had a concomitant osteotomy of the femur to align the knee joint parallel to the floor. The results were good in five patients and fair in two.
A retrospective review of our experience with fractures after 27 Wagner limb lengthenings (23 patients) was undertaken. Ten fractures occurred after lengthening in eight patients (six spontaneous, four traumatic). Seven patients fractured despite a "staged" removal of the fixation plate. Seven of 10 fracture patients required open reduction/internal fixation (ORIF) to obtain union and/or satisfactory alignment. Our results indicate that patients with a congenital limb length inequality are prone to spontaneous fracture after Wagner limb lengthening. These results raise serious questions regarding the quality of bone healing after a Wagner-type lengthening for congenital limb length inequality.
One hundred sixty patients with idiopathic scoliosis treated with Cotrel-Dubousset instrumentation (CDI) underwent preoperative and postoperative sagittal plane analysis of the thoracic spine, thoracolumbar junction, and lumbar spine. The data suggest that mild to moderate improvements in thoracic hypokyphosis are possible. When crossing the thoracolumbar junction, reversal of rod bend and reversal of hooks on the derotation rod appear to provide the most physiologic sagittal contour. Cotrel-Dubousset instrumentation to the mid and distal lumbar spine can preserve and, at times, enhance lumbar lordosis.
One hundred sixty patients with idiopathic scoliosis underwent preoperative and postoperative sagittal plane analysis of the thoracic spine, thoracolumbar junction, and lumbar spine. The data suggest that mild to moderate improvements in thoracic hypokyphosis are possible. When crossing the thoracolumbar junction, reversal of rod bend and reversal of hooks on the derotation rod appears to provide the most physiologic sagittal contour. Cotrel-Dubousset instrumentation to the mid and distal lumbar spine can preserve and, at times, enhance lumbar lordosis.
Relative stretching of the cauda equina over the posterosuperior border of the sacrum can be found in all patients who have Grade-III or IV spondylolisthesis at the lumbosacral junction. We identified twelve patients, all less than eighteen years old, who had cauda equina syndrome after in situ arthrodesis for Grade-III or IV lumbosacral spondylolisthesis. In all twelve patients, posterolateral arthrodesis had been done bilaterally through a midline or paraspinal muscle-splitting approach. Nothing in the operative reports suggested that the cauda equina had been directly injured during any of the procedures. Five of the twelve patients eventually recovered completely. The remaining seven patients had a permanent residual neurological deficit, manifested by complete or partial inability to control the bowel and bladder. If dysfunction of the root of the sacral nerve is noted preoperatively in a patient who has lumbosacral spondylolisthesis, decompression of the cauda equina concomitant with the arthrodesis should be considered. An acute cauda equina syndrome that follows a seemingly uneventful in situ arthrodesis for spondylolisthesis is best treated by an immediate decompression that includes resection of the posterosuperior rim of the dome of the sacrum and the adjacent intervertebral disc. In addition, posterior insertion of instrumentation and reduction of the lumbosacral spondylolisthesis should be considered.
Twenty skeletally mature patients (average age, sixteen years and seven months; range, thirteen years and seven months to twenty-two years and four months) were treated for limb-length inequality by closed shortening of the femur. Preoperatively, the amount of femoral shortening that was necessary to level the pelvis was determined radiographically by balancing the pelvis with calibrated lifts under the shorter extremity. All twenty shortening procedures were performed with an intramedullary cam saw and insertion of an intramedullary rod through a gluteal incision; no additional incisions were needed to complete the procedure. At the most recent follow-up, the limb-length discrepancy was one centimeter or less in all twenty patients. All patients reported that the limbs seemed to be of equal length and that the pelvis felt level.
Fifty-seven patients (seventy-one limbs) who had congenital longitudinal deficiency of the tibia (tibial hemimelia) were retrospectively categorized according to radiographic type (Types 1 through 4, as described by Jones et al.). At an average follow-up of nine years, fifty-six of fifty-seven patients walked independently. An ablative surgical procedure was performed on sixty-one of the seventy-one lower extremities. According to the classification of Jones et al., fifty-four limbs had a Type-1 (a or b) or Type-2 deficiency. In twenty-two of these extremities, disarticulation of the knee was performed; in twenty-five, a Syme amputation; and in one, a Chopart amputation. The ipsilateral foot was retained in six extremities that had a severe Type-1 or Type-2 deficiency. Medial transfer of the fibula (the Brown procedure) generally yielded less than satisfactory results; in ten of fourteen extremities, one or more additional operations were needed. Seventeen extremities were classified as having a Type-3 or Type-4 deficiency; Syme amputation was done in nine and Chopart amputation, in four. Despite satisfactory reconstruction of the ankle, a Syme amputation was necessary in most extremities that had a Type-4 deficiency because a major leg-length discrepancy was projected. In four limbs that had a Type-3 or Type-4 deficiency, the foot was retained.
Over a 7-year period (1984-1991), nine patients (aged 10-18 years) with 13 involved extremities were operatively treated for symptomatic severe torsional malalignment of the lower extremity and associated patellofemoral pathology. Physical examination and analysis of gait revealed severe rotational deformity characterized by excessive femoral anteversion and external tibial torsion. The cosmetic and functional pathologic effect of this torsional malalignment was centered about the knee joint. In all patients, conservative treatment, including therapy for muscle strengthening and nonsteroidal medication, was unsuccessful in alleviating suspected patellofemoral pain. Subsequent definitive operative treatment in all 13 extremities consisted of corrective osteotomies, internally rotating the distal part of the tibia or externally rotating the distal part of the femur or both. Osteotomies were performed as close to the knee joint as possible. No additional soft-tissue procedures were performed directly to affect patellar tracking. All osteotomies healed without complications. At an average follow-up of 2 years + 7 months (range, 18-48 months) overall, patients had an improvement in gait pattern, extremity appearance, and a marked decrease in knee pain.