Fluorescence quenching of fluorescein by R-phycoerythrin. A pitfall in dual fluorescence analysis.

The use of a single laser fluorescence-activated cell sorter (FACS) to analyse cellular subpopulations by immunochemical staining requires an alternative dye to fluorescein with appropriate spectral characteristics. R-phycoerythrin (RPE) is widely employed for this purpose. In this study the ability of RPE to quench the fluorescein emission when both are attached to the same cell has been demonstrated by dual labelling of tonsil lymphocytes with pairs of monoclonal antibodies. Reduction of the fluorescein signal correlated with the amount of RPE attached and the relative intensity of emission from the two fluorochromes. The possible photochemical mechanisms which result in a reduction of the fluorescein signal by RPE are discussed. The inclusion of control tests, in which RPE is omitted, is recommended in order to avoid misinterpretation of the results of subpopulation analysis by single laser FACS - especially when low levels of fluorescein staining are obtained.

Neoadjuvant chemoradiotherapy for esophageal cancer: is it worthwhile?

BACKGROUND: With promising results from several institutions, many centers began treating patients with esophageal cancer with neoadjuvant chemoradiotherapy (NC) followed by esophagectomy. This approach is demanding for the patient and has not been proved to be better than esophagectomy alone. OBJECTIVE: To assess survival time and measures of quality of life associated with NC. DESIGN: A retrospective review during 1990 to 1996. SETTING: The 3 tertiary academic hospitals affiliated with the University of Massachusetts Medical School, Worcester. PARTICIPANTS: All patients (N=51) with cancer of the middle or lower esophagus who were treated with NC followed by esophagectomy during this period. MAIN OUTCOME MEASURES: Median and 1-, 2-, and 3-year survival times; median preoperative treatment time (first office visit for surgical consultation before beginning NC to the date of surgery), median hospital stay, and postoperative swallowing function. RESULTS: The median survival time of all patients was 16.3 months; 1-, 2-, and 3-year overall survival rates were 67%, 46%, and 39%, respectively. The median hospital stay was 12 days. The median postoperative treatment time was 3.3 months, which was 20% of the median survival time. Of the 51 patients, 19 were alive with a median follow-up time of 2.5 years. Twenty-nine percent of the patients had a complete pathological response with median and 1-, 2-, and 3-year survival rates of 17.5 months, 73%, 57%, and 57%, respectively. Palliation of dysphagia was excellent, with 44 (93%) of 47 operative survivors taking either a soft diet (18 [38%]) or a regular (26 [55%]) diet by the first postoperative visit. CONCLUSIONS: Median survival time with NC followed by esophagectomy for resectable cancer of the esophagus does not appear to be significantly better than that reported for esophagectomy alone. Further, treatment time with NC consumed 20% of survival time. Examining only these outcome variables suggests that NC is not worth-while. However, examining a longer-term outcome survival variable, such as 3-year survival time, suggests that NC followed by esophagectomy may result in greater long-term survival than that reported for esophagectomy alone. We conclude that further randomized, controlled studies are necessary before NC followed by esophagectomy is considered superior to esophagectomy alone for the treatment of resectable esophageal cancer.

The surgical management of pulmonary metastasis: current concepts.

Lung metastases have been found in 25-30% of all patients with cancer at autopsy. Those patients satisfying criteria for surgical resection represent a much smaller subgroup. Given the potentially curative nature of pulmonary metastasectomy in the absence of disseminated disease, it has become widely accepted as an important treatment option for a variety of malignancies with metastasis to the lungs. A standardized approach remains unfounded however, given limited numbers of patients, various histologic subtypes and few published studies utilizing randomized prospective methodology.Ultimately, the development of metastasis represents a major determinant of survival for patients with cancer. Pulmonary metastasectomy is an important treatment modality for patients with metastatic pulmonary disease. The indications for pulmonary metastasectomy and the surgeon's role in pulmonary metastatic disease continue to evolve. Future prospective studies and the compilation of comparable data yielding prognostic factors for specific histologies will better define indications for resection.

The use of fluorescent probes in immunochemistry.

The limitations and advantages of particular dyes for labelling proteins and other biological materials are discussed. Methods available for conjugating dyes to proteins are outlined. Following a discussion of double labelling methods the use of photoactivatable fluorochromes and time resolved fluorescence methodologies are outlined. The reasons for the photoinstability of some fluorochromes are discussed and methods for overcoming the problem are described.

Orthopaedic complications of Lyme disease in children.

Lyme disease is transmitted by the tick Ixodes dammini ("deer tick") or a related ixodid tick. Early diagnosis of children with Lyme disease is difficult because the bite of the ixodid tick often goes unnoticed. Furthermore, erythema chronicum migrans, the characteristic rash of the disease, occurs in less than 50% of cases. However, an awareness of orthopaedic complications of Lyme disease may facilitate an early diagnosis of this disease. Orthopaedic complications of Lyme disease include those which are oligoarticular in nature. Brief intermittent attacks of swelling and pain in one or more joints--primarily large ones--is the pattern of disease most frequently presented. The knee is the joint most commonly affected. In most cases, pain is not severe enough to debilitate the patient or prevent weight-bearing activity. An elevated sedimentation rate is the only consistently abnormal routine laboratory finding in Lyme disease. The only radiographic abnormalities noted in children are effusion and osteopenia. However, the radiograph of a patient known to have Lyme disease may not show any abnormalities at all. Lyme disease shares symptoms in common with septic arthritis and juvenile rheumatoid arthritis. Whenever a distinction between Lyme arthritis and septic arthritis is difficult to make, treatment should be directed at septic arthritis while serological tests for Lyme disease are pending. The physician should consider Lyme disease to be a possible diagnosis of any patient with arthritis and a history of rash or fever, idiopathic neurological disease, or a cardiac conduction defect--especially if there is a history of possible exposure to the carrier tick.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance imaging of skewfoot.

Magnetic resonance imaging was used to visualize the ossified and unossified portions of the bones and soft tissues of the feet in order to evaluate the tarsometatarsal anatomy in sixteen children, three months to six years old (mean, fifteen months old), who were seen in the orthopaedic clinic with a suspected diagnosis of skewfoot. Twenty-seven feet were clinically abnormal and five were normal. Of the abnormal feet, twenty-six had a radiographic diagnosis of skewfoot and one, of simple metatarsus adductus. Of the skewfeet, seven had a talocalcaneal angle of 45 degrees or more as measured on the lateral radiograph and six had a talocalcaneal angle of 45 degrees or more as measured on the anterior radiograph. Valgus deformity of the hindfoot was not apparent on clinical examination in any of the children. The talocalcaneal angles measured on the magnetic resonance images corresponded poorly with those measured on the radiographs, possibly because it is not possible to simulate weight-bearing during magnetic resonance imaging or because the effect of partial volume averaging on thin sections. However, magnetic resonance imaging demonstrated the shapes of the bones and the positions of the unossified portions of the bones. Magnetic resonance imaging showed lateral subluxation of the navicular in twenty-four skewfeet, plantar subluxation in ten, and medial subluxation of the first metatarsal on the medial cuneiform in twenty-five. The alignment of the lateral margin of the calcaneus and cuboid on the magnetic resonance images was normal in all patients. Magnetic resonance imaging has the unique ability to show the cartilaginous and ossified portions of the developing bones of the foot.

Ultrasonographic evaluation of the elbow in infants and young children after suspected trauma.

Fractures and epiphyseal injuries in the region of the elbow are uncommon in infants and young children, but they can be very difficult to diagnose and delineate accurately. In addition to plain radiography, invasive or costly procedures such as arthrography and magnetic resonance imaging traditionally have been used to evaluate these injuries. We used high-resolution real-time ultrasonography to evaluate a suspected injury of the elbow in seven infants and one ten-year-old child. Three of the infants had a physeal separation, two had a supracondylar fracture, and two had no skeletal injury. The child had an avulsion fracture of the lateral epicondyle of the humerus and an effusion in the joint. The ultrasonographic findings were confirmed by arthrography in three patients, by open reduction in one, and by follow-up radiographs in all. None of the ultrasonographic studies were performed with the patient under general anesthesia. Ultrasonography, a readily available, non-invasive technique, can be used to evaluate the unossified epiphysis about the elbow of infants and young children; to demonstrate dislocations, fractures, and physeal separations; to identify a hinge of soft tissue at the site of a fracture; to identify interposition of soft tissue between fracture fragments; and to aid in the planning of closed and open reductions.

Complications in children managed with immobilization in a halo vest.

Thirty-seven patients who were three to sixteen years old were managed with immobilization in a halo vest between 1987 and 1993. Twenty-four patients (65 per cent) had the halo vest applied in conjunction with operative arthrodesis of the cervical spine; the remaining thirteen patients (35 per cent) had the halo vest applied to immobilize the cervical spine after trauma. Complications occurred in twenty-five patients (68 per cent). Pin-site infections were the most common complications, developing in twenty-two patients. Grade-II infections (purulent drainage) developed more frequently in children who were eleven years old or more: they were identified in five of fourteen such patients, compared with two of twenty-three patients who were ten years old or less. There was a tendency toward more grade-I infections (non-purulent drainage, with or without erythema) and loosening of the pins in the children who were ten years old or less: eleven of twenty-three such patients had each of those complications, compared with four of fourteen children who were eleven years old or more. Both loosening and infection occurred more frequently at the anterior pin sites. Other complications included one dural penetration, one transient injury of the supraorbital nerve, and three pin-site scars that were considered by the family to be objectionable. There were no complications related to the vest part of the halo vest. Younger patients who had a halo construct with more than four pins (multiple-pin constructs) had a similar rate of complications compared with patients who were managed with a standard four-pin halo construct.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative anaphylaxis due to exposure to latex (natural rubber) in children.

Intraoperative anaphylaxis secondary to exposure to latex is a serious and potentially life-threatening phenomenon that has been recognized more frequently in recent years. Between 1989 and 1992, twenty-one patients had a Type-I (anaphylactic) reaction to latex intraoperatively at The Children's Hospital of Philadelphia. Twelve (57 per cent) of these patients had spina bifida. Six patients (29 per cent) had cerebral palsy, and five of them had a ventriculoperitoneal shunt. Of the remaining three patients, one (5 per cent) had exstrophy of the bladder, one had VATER syndrome, and one had Duchenne muscular dystrophy. All of the patients had had at least two previous operative procedures. Overall, sixteen patients (76 per cent) had a ventriculoperitoneal shunt. The manifestations of the allergic reaction included a rash in fifteen patients (71 per cent), hypotension in fifteen, tachycardia in eleven (52 per cent), bronchospasm in ten (48 per cent), bradycardia in two (10 per ent), and cardiac arrest in two. The symptoms occurred within minutes after the induction of the anesthesia in all but one patient, in whom hypotension and cardiovascular arrest developed approximately one hour after the beginning of the operation. Two patients had a full cardiopulmonary arrest while under the anesthesia. All twenty-one patients responded to management; there were no deaths. Of the six patients who had cerebral palsy, five had been managed with a ventriculoperitoneal shunt because of hydrocephalus following a previous intraventricular hemorrhage that was related to prematurity.(ABSTRACT TRUNCATED AT 250 WORDS)

Neural injuries associated with supracondylar fractures of the humerus in children.

A retrospective review of displaced extension-type supracondylar fractures of the humerus in 101 children who were seen consecutively revealed eighteen associated neural injuries in thirteen children. Nine of the neural injuries in eight patients spontaneously resolved at a mean of 2.5 months (range, 1.5 to five months) after injury. The remaining nine lesions in five patients were explored at a mean of 7.5 months (range, five to fourteen months) after injury, because clinical and electromyographic studies showed no return of function. Neurolysis was performed on eight of the nerves that were explored (in five patients), and the remaining radial nerve was found to be completely lacerated and needed nerve-grafting. The length of follow-up after neurolysis averaged twenty-five months (range, thirteen to forty-four months). All five patients had functional recovery, as documented by range-of-motion, grip-strength and lateral pinch-strength, and von Frey and two-point-discrimination sensory testing. The patient who had had nerve-grafting never recovered neural function, and tendon transfers were needed. We concluded that observation and supportive therapy is the preferred initial approach for children who have a neural injury associated with a closed, displaced supracondylar fracture of the humerus. However, if there is no clinical or electromyographic evidence of return of neural function at five months after injury, exploration and neurolysis should be performed. If the nerve is in continuity, the prognosis after neurolysis is excellent.

Lyme arthritis in children. An orthopaedic perspective.

The cases of forty-three children with clinical and serological evidence of Lyme arthritis that was diagnosed between August 1983 and July 1985 were evaluated. The mean length of follow-up was twenty months, with a range of five to thirty months. All of the children lived in or had visited an area where the disease was known to be endemic. Arthritis was the presenting feature in more than half of the children, and half of the children had initially consulted an orthopaedic surgeon, none of whom made the correct diagnosis. Only twenty patients had a history of erythema chronicum migrans, the characteristic rash that precedes the arthritis, and for only nineteen children was there any recollection of having been bitten by a tick. Three patients had Bell palsy and one had a popliteal cyst in conjunction with the arthritis. All of the patients had oligoarticular involvement. The knee was involved in all but two patients. Recurrent attacks of synovitis were common. Effusion was the only radiographic abnormality that was observed, and it was found in thirty-two patients. The sedimentation rate was elevated in thirty of thirty-six patients. Immunofluorescent serology for Lyme disease, which is sensitive and specific, was uniformly positive. Of thirty-three patients who were treated with oral administration of penicillin or tetracycline alone, thirty-one responded, while two patients who had recurrent attacks of the disease responded to parenteral administration of antibiotics. The remaining ten patients responded to combinations of orally and parenterally administered antibiotics. Longer follow-up is needed to further document the apparently low rate of relapse after antibiotic therapy in this young population.

Slipped capital femoral epiphysis. The prevalence of late contralateral slip.

We evaluated the prevalence of slipped capital femoral epiphysis in the contralateral hip of 169 children who had been managed with pinning in situ and thirty who had been managed with immobilization in a spica cast. Only children who had initially been seen with a unilateral slip and had been followed for a minimum of two years or until skeletal maturity were included in the study. The average duration of follow-up was 3.6 years (range, 0.5 to 9.5 years) for the group that had been managed with a cast and 2.8 years (range, 1.0 to 8.3 years) for the group that had been managed operatively. In sixty-one (36 per cent) of the 169 patients who had had operative treatment and two (7 per cent) of the thirty who had been managed with a spica cast, a slip subsequently developed in the contralateral hip; this difference was significant (p = 0.001). On the basis of these findings, we recommend that closer attention be paid to the potential development of a slip in the contralateral hip after pinning.

Displaced fractures of the hip in children. Management by early operation and immobilisation in a hip spica cast.

Fractures of the hip in children have been associated with a very high rate of serious complications including avascular necrosis (up to 47%) and coxa vara (up to 32%). Over a period of 20 years, we have treated displaced fractures by early anatomical reduction, internal fixation and immobilisation in a spica cast to try to reduce these complications. We have reviewed 18 patients who had a displaced non-pathological fracture of the hip when under 16 years of age. Their mean age at the time of the injury was eight years (2 to 13). They returned for examination and radiography at a mean follow-up of eight years (2 to 17). Each patient had been treated by early (" 24 hours) closed or open reduction with internal fixation and 16 had immobilisation in a spica cast. By Delbet's classification, there was one type-I, eight type-II, eight type-III, and one type-IV fractures. There were no complications in 15 patients. Avascular necrosis occurred in one patient (type-III), nonunion in one (type-II, one of the two patients who did not have a cast) and premature physeal closure in one (type-I). There were no cases of infection or complications as a result of the cast. Our treatment of displaced hip fractures in children by early reduction, internal fixation, and immobilisation in a spica cast gave reduced rates of complications compared with that of large published series in the literature.

Torticollis in children.

Torticollis is a common clinical sign that is found in a variety of disorders. Childhood torticollis differs from the adult form in that congenital types are common and many frequently encountered disorders found in adults are unusual. Pediatric torticollis related to otolaryngologic conditions is reviewed, and three illustrative cases are presented.

Operant stimulus control applied to maze behavior: heat escape conditioning and discrimination reversal in Alligator mississippiensis.

Eight alligators were trained to escape heat by traversing an 8-ft runway containing right or left approaches to a water tank. All subjects were run until they had satisfied three criteria of stable response time, after which the predominant escape path was blocked, requiring discrimination reversal. Seven subjects again met the criteria; three also met them in a second reversal.

When does the flat-top talus lesion occur in idiopathic clubfoot: evaluation with magnetic resonance imaging at three months of age.

Flat-top talus has been described as a pathologic change secondary to idiopathic clubfoot condition and/or as a direct result of nonoperative manipulation involving forced dorsiflexion and molding of the cartilaginous talus. No definitive study, however, on the etiology and the timing of the flat-top talus deformity has been performed to date. The authors evaluated the magnetic resonance images of eleven patients with idiopathic clubfoot deformities treated with 2 to 3 months of casting to assess if flattening of the talar dome occurred at this age with this amount of casting. All children were 3 months of age, were casted for a maximum of 2 to 3 months, and sedated before MRI examination. The images were evaluated for maximum talar head height, maximum talar body height, and deviation of the talar body from a perfect circle. Maximum talar head height ranged from 4 to 9 mm, maximum talar body height ranged from 6 to 10 mm. Eight of the eleven had maximum talar body measurements 3 to 5mm greater than maximum talar head height. Three of the eleven patients had head and body size of equal proportion. Two of the eleven had a talar body that was within 1 mm of a perfect circle. The remaining nine patients had perfectly round talar bodies. In the senior author's (RSD) experience with treating clubfeet, a substantial increase has been seen at operation in flat-top tali among children that were casted for more than 1 year before surgical correction, compared to children casted for 3 months before surgical correction. The current investigation indicated that although tali of children with clubfeet are abnormally shaped, the talar body remains larger than the talar head and maintains its roundness after two to three months of corrective casting. Maintenance of cast treatment for more than three months may lead to the flat-top talus deformity. The authors recommend surgical intervention following three months of failed manipulation and casting to prevent this deformity.

Talo-navicular arthrodesis for residual midfoot deformities of a previously corrected clubfoot.

Triangular navicular, dorsal-lateral subluxation of the talo-navicular (TN) joint with a secondary forefoot cavovarus deformity, and degenerative changes of the TN joint are frequent causes of residual clubfoot deformity and pain in the midfoot after surgical correction. This study investigates the usefulness of TN arthrodesis to correct these deformities and to resolve symptoms resulting from these deformities. During the period from 1991-1996, the senior author performed 19 TN fusions (16 patients) for the above residual clubfoot deformities involving a painful TN joint. Eight of the procedures (seven patients) also required a lateral column shortening with a calcaneal wedge osteotomy to allow for a complete correction of the TN joint. The procedure was only performed in cases involving a hindfoot that was adequately aligned during a previous clubfoot correction. The average age of the patients at the time of surgery was 11 years (range: 4-20). One patient (bilateral procedures) was lost to follow-up. Fifteen patients (17 procedures) were followed-up for an average of four years (range: 2-6). All patients reported symptomatic improvement after the TN arthrodesis. Fourteen of the patients (15 procedures) were completely satisfied. The remaining patient (bilateral procedures) was only partially satisfied due to the subsequent development of navicular-cuneiform osteoarthritis in both feet. Two cases (2 patients) developed complications requiring a second procedure for satisfactory results. In addition, the procedure resulted in an improvement of the talus-first metatarsal angle on both antero-posterior and lateral radiographs. TN arthrodesis produced a correction of the residual clubfoot deformities of the midfoot and resulted in satisfactory clinical improvement in all the patients.

Distraction osteogenesis for congenitally short lesser metatarsals.

Six lesser metatarsal lengthening procedures were performed in three patients using a miniature external fixator to perform distraction osteogenesis. The metatarsals were lengthened an average of 15.5 mm. The external fixator was left in place for an average of 15.5 weeks, with additional time in a cast or cast shoe. Complications included five occurrences of infection, two cases of premature healing of the osteotomy, one nondisplaced fracture through the new bone formation, and hypertrophic granulation at a pin site. While all metarasals were successfully lengthened, two rays (one patient) had symptomatic stiffness at the metatarsophalangeal joint with continued metatarsalgia.

Growth disturbances after distal tibial physeal fractures.

Twenty-four patients with distal tibial growth disturbance were reviewed. Disturbances were classified as physeal bar (prior to deformity), angular, linear or combined deformities. Treatment consisted of osteotomy in fourteen, epiphyseodesis in seven, excision of bony bar in two, and observation in one patient. Follow up was an average 36.6 months (range 4-129 months) after treatment of growth disturbance. The age at time of injury was 10.4 years of age average (range 3-15 years). There were 12 SH2, 2 SH3, 7 SH4, and 3 SH5 distal tibial physeal fractures. Thirteen of 15 fractures considered high energy and only 1 of 9 fractures considered low energy resulted in angular deformity. Angular and linear deformities presented an average 46 months (range 12-120 months) and physeal bars at an average 14 months (range 6-25 months) after injury. Patients with a delay in presentation of growth disturbance greater than 24 months had angular deformities in 92% compared with 33% in children presenting less than or at 24 months. Treatment based on type of deformity, age at time of injury, and growth remaining was considered successful in 83%. Patients with angular or linear deformities were more likely to present late, have high energy injuries, be male patients and have Salter-Harris types IV and V. Early diagnosis and treatment of growth disturbance can prevent severe deformity.

Metatarsal lengthening.

Metatarsal lengthening for brachymetatarsia is a good procedure that can improve appearance and function. There are risks to these procedures, which should be understood thoroughly.