Long-term benefits of deflazacort treatment for boys with Duchenne muscular dystrophy in their second decade

We compare the clinical course of 74 boys 10-18 years of age with Duchenne muscular dystrophy (DMD) treated (40) and not treated (34) with deflazacort. Treated boys were able to rise from supine to standing, climb stairs and walk 10 m without aids, 3-5 years longer than boys not treated. After 10 years of age, treated boys had significantly better pulmonary function than boys not treated and after 15 years of age, 8 of 17 boys not treated required nocturnal ventilation compared with none of the 40 treated boys. For boys over 15 years of age, 11 of 17 boys not treated required assistance with feeding compared to none of the treated boys. By 18 years, 30 of 34 boys not treated had a spinal curve greater than 20 degrees compared to 4 of 40 treated boys. By 18 years, 7 of 34 boys not treated had lost 25% or more of their body weight (treated 0 of 40) and 4 of those 7 boys required a gastric feeding tube. By 18 years, 20 of 34 boys not treated had cardiac left ventricular ejection fractions less than 45% compared to 4 of 40 treated boys and 12 of 34 died in their second decade (mean 17.6 +/- 1.7 years) primarily of cardiorespiratory complications. Two of 40 boys treated with deflazacort died at 13 and 18 years of age from cardiac failure. The treated boys were significantly shorter, did not have excessive weight gain and 22 of 40 had asymptomatic cataracts. Long bone fractures occurred in 25% of boys in both the treated and not treated groups. This longer-term study demonstrates that deflazacort has a very significant impact on health, quality of life and health care costs for boys with DMD and their families, and is associated with few side effects.

Abnormal vertebral segmentation and the notch signaling pathway in man

Abnormal vertebral segmentation (AVS) in man is a relatively common congenital malformation but cannot be subjected to the scientific analysis that is applied in animal models. Nevertheless, some spectacular advances in the cell biology and molecular genetics of somitogenesis in animal models have proved to be directly relevant to human disease. Some advances in our understanding have come through DNA linkage analysis in families demonstrating a clustering of AVS cases, as well as adopting a candidate gene approach. Only rarely do AVS phenotypes follow clear Mendelian inheritance, but three genes-DLL3, MESP2, and LNFG-have now been identified for spondylocostal dysostosis (SCD). SCD is characterized by extensive hemivertebrae, trunkal shortening, and abnormally aligned ribs with points of fusion. In familial cases clearly following a Mendelian pattern, autosomal recessive inheritance is more common than autosomal dominant and the genes identified are functional within the Notch signaling pathway. Other genes within the pathway cause diverse phenotypes such as Alagille syndrome (AGS) and CADASIL, conditions that may have their origin in defective vasculogenesis. Here, we deal mainly with SCD and AGS, and present a new classification system for AVS phenotypes, for which, hitherto, the terminology has been inconsistent and confusing.

Suppressor of fused negatively regulates beta-catenin signaling

Suppressor of fused (Su(fu)) is a negative regulator of the Hedgehog signaling pathway that controls the nuclear-cytoplasmic distribution of Gli/Ci transcription factors through direct protein-protein interactions. We show here that Su(fu) is present in a complex with the oncogenic transcriptional activator beta-catenin and functions as a negative regulator of T-cell factor (Tcf)-dependent transcription. Overexpression of Su(fu) in SW480 (APC(mut)) colon cancer cells in which beta-catenin protein is stabilized leads to a reduction in nuclear beta-catenin levels and in Tcf-dependent transcription. This effect of Su(fu) overexpression can be blocked by treatment of these cells with leptomycin B, a specific inhibitor of CRM1-mediated nuclear export. Overexpression of Su(fu) suppresses growth of SW480 (APC(mut)) tumor cells in nude mice. These observations indicate that Su(fu) negatively regulates beta-catenin signaling and that CRM-1-mediated nuclear export plays a role in this regulation. Our results also suggest that Su(fu) acts as a tumor suppressor.

Prenatal diagnosis and the pediatric surgeon: the impact of prenatal consultation on perinatal management

PURPOSE

Pediatric surgeons are increasingly called on by obstetrical colleagues to counsel parents about the implications of a prenatal ultrasound finding. Our understanding of the natural history of many prenatally diagnosed surgical conditions has grown significantly in recent years. Whether prenatal surgical consultation can influence perinatal course had not been investigated.

METHODS

During an 21-month period, 12,865 prenatal ultrasound studies were performed on a total of 4,551 patients, and 221 prenatal surgical consultations were obtained through a newly established fetal treatment program at a tertiary care prenatal diagnostic center. To evaluate the impact of prenatal pediatric surgical consultation on perinatal course, the authors reviewed changes in management including termination of pregnancy, in utero intervention, and altered site, mode, or timing of delivery.

RESULTS

Two hundred twenty-one fetuses were referred for consultation; their 234 congenital anomalies included genitourinary (36%), thoracic (16%), intraabdominal (14.5%), abdominal wall (10.6%), neurological (9%), skeletal (6%), and head and neck (2.5%) defects; 2.5% had tumors and 2.5% were twin pregnancies. Pregnancy was terminated in 9.5% of cases, because of patient request, chromosomal abnormality, or dismal prognosis. In 3.6%, the decision to terminate was changed as a result of consultation. Site of delivery was changed as a result of consultation in 37% to facilitate postnatal evaluation and initiate immediate treatment. Mode of delivery was changed in 6.8% to prevent dystocia, hemorrhage into a tumor, as in sacrococcygeal teratoma, or to provide an emergency airway, as in cervical teratoma. The timing of delivery was changed in 4.5% to avoid further damage to fetal organs in cases of obstructive uropathy, gastroschisis, sacrococcygeal teratoma with high-output failure, and hydrocephalus. Five percent (11) underwent treatment in utero for fetal hydrothorax, obstructive uropathy, twin-twin transfusion syndrome, or lymphangioma. The overall perinatal mortality rate was 2.5%.

CONCLUSION

Prenatal pediatric surgical consultation may have a significant impact on the perinatal management of the fetus with a surgically correctable congenital anomaly. Providing obstetric colleagues and families with valuable insight into the surgical management of anomalies allows fetal intervention when appropriate, and delivery in an appropriate setting, by the safest mode of delivery, and at the gestational age appropriate to minimize effects of the anomaly.

Deflazacort in Duchenne muscular dystrophy: a comparison of two different protocols

We compare the long-term benefits and side effects of deflazacort using two treatment protocols from Naples (N) and Toronto (T). Boys with Duchenne muscular dystrophy between the ages of 8 and 15 years and who had four or more years of deflazacort treatment were reviewed. Diagnostic criteria included males with proximal muscle weakness evident before 5 years, increased serum creatine kinase and genetic testing and/or a muscle biopsy consistent with Duchenne muscular dystrophy. Thirty-seven boys were treated with protocol-N using deflazacort at a dose of 0.6 mg/kg per day for the first 20 days of the month and no deflazacort for the remainder of the month. Boys with osteoporosis received daily vitamin D and calcium. Deflazacort treatment started between 4 and 8 years of age. Thirty-two were treated with protocol-T using deflazacort at a dose of 0.9 mg/kg per day, plus daily vitamin D and calcium. Treatment started between 6 and 8 years of age. All boys were monitored every 4-6 months. The results were compared with age-matched controls in the two groups (19 for protocol-N and 30 for protocol-T). For the boys treated with protocol-N, 97% were ambulatory at 9 years (control, 22%), 35% at 12 years (control, 0%), 25% at 15 years (control, 0%). For the 32 boys treated with protocol-T, 100% were ambulatory at 9 years (control, 48%), 83% at 12 years (control, 0%) and 77% at 15 years (control, 0%). No aids or leg braces were used for ambulation. In boys 13 years and older, a scoliosis of >20 degrees developed in 30% of the boys on protocol-N, 16% on protocol-T and 90% of controls. For protocol-N, no cataracts were observed while in protocol-T, 30% of boys had asymptomatic cataracts that required no treatment. Fractures occurred in 19% (control 16%) of boys on protocol-N and 16% (control, 20%) of boys on protocol-T. This report illustrates: (a) the importance of collaborative studies in developing treatment protocols in Duchenne muscular dystrophy and (b) the long-term beneficial effects of deflazacort treatment in both protocols. However, the protocol-T seems to be more effective and frequently is associated with asymptomatic cataracts.

Sensitivity of a clinical examination to predict need for radiography in children with ankle injuries: a prospective study

BACKGROUND

Radiographs are ordered routinely for children with ankle trauma. We assessed the predictive value of a clinical examination to identify a predefined group of low-risk injuries, management of which would not be affected by absence of a radiograph. We aimed to show that no more than 1% of children with low-risk examinations (signs restricted to the distal fibula) would have high-risk fractures (all fractures except avulsion, buckle, and non-displaced Salter-Harris I and II fractures of the distal fibula), and to compare the potential reduction in radiography in children with low-risk examinations with that obtained by application of the Ottawa ankle rules (OAR).

METHODS

Standard clinical examinations and subsequent radiographs were prospectively and independently evaluated in two tertiary-care paediatric emergency departments in North America. Eligible participants were healthy children aged 3-16 years with acute ankle injuries. Sample size, negative and positive predictive values, sensitivity, and specificity were calculated. McNemar's test was used to compare differences in the potential reduction in radiographs between the low-risk examination and the OAR.

FINDINGS

607 children were enrolled; 581 (95.7%) received follow-up. None of the 381 children with low-risk examinations had a high-risk fracture (negative predictive value 100% [95% CI 99.2-100]; sensitivity 100% [93.3-100]). Radiographs could be omitted in 62.8% of children with low-risk examinations, compared with only 12.0% reduction obtained by application of the OAR (p<0.0001).

INTERPRETATION

A low-risk clinical examination in children with ankle injuries identifies 100% of high-risk diagnoses and may result in greater reduction of radiographic referrals than the OAR.

A germline mutation at the extreme 3' end of the APC gene results in a severe desmoid phenotype and is associated with overexpression of beta-catenin in the desmoid tumor

Desmoid tumors arise sporadically or as part of the extraintestinal manifestations of familial adenomatous polyposis (FAP). In FAP, two distinct clinical presentations of the desmoid phenotype are seen: 1) one or a few desmoid tumors present predominantly in the abdominal wall or the abdomen; 2) a florid proliferation of tumors early in life, mostly near the axial skeleton or extremities. These different phenotypes have been associated with different sites of germline mutations in the adenomatous polyposis coli gene (APC gene). We present a large, French-Canadian kindred with a florid desmoid tumor phenotype caused by a germline mutation at codon 2643-2644 of the APC gene. The phenotype was characterized by the early onset of multiple tumors, arising near the axial skeleton and in proximal extremities. The penetrance of desmoid tumors was near 100% in this kindred. However, the expression of the disease was variable amongst the different affected relatives. Many gene carriers had cutaneous cysts. Polyposis of the colon was rarely observed in the affected individuals and we did not document upper gastro-intestinal polyps. The mutant APC allele did not express a stable truncated protein in vivo. Molecular analysis of the proband's tumor DNA revealed a somatic inactivating mutation of the wild-type allele. Immunohistochemistry on the tumor also demonstrated elevated levels of beta-catenin. The present study demonstrates that this extreme 3' APC mutation is associated with a severely penetrant desmoid phenotype and attenuated polyposis coli. It also suggests the involvement of the beta-catenin pathway in the development of desmoid tumors in FAP. The natural history of the disease is variable between individuals, and surgical interventions have to be timed appropriately due to the frequent recurrences.

Amniotic band syndrome in fetal lambs. I: Fetoscopic release and morphometric outcome

A fetal lamb model of amniotic band syndrome (ABS) was developed to study the pathophysiology of banded extremities and evaluate the possibility of in utero treatment with the potential for functional recovery. Eight fetal lambs underwent banding of their extremities with umbilical tape at 100 days' gestation. Two lambs aborted after the open fetal surgery. The limbs of two unoperated newborn lambs served as controls in addition to five sham-operated control limbs that had no bands applied. Nine limbs were banded without reducing blood flow assessed by laser doppler (group 1), and 6 limbs were similarly banded and released fetoscopically at 125 days' gestation. Four limbs were banded, with a mean reduction in blood flow to the limb of 18.7% (group 2) by laser doppler flowmeter. Shortly after birth the lambs were killed, and segmental limb length, circumference, joint range of motion, and histology were evaluated. At birth, banded limbs showed marked brawny edema and absence of wool distal to the band. Segmental limb measurements showed shorter distal forelimbs in banded limbs compared with controls (10.97 +/- 0.59 versus 12.98 +/- 0.69, P < .05). Banded limbs were associated with progressive increase in hoof circumference (P < .03) and a decrease in joint range of motion (P < .003). In sharp contrast, there were no differences between fetoscopically released limbs and control limbs in any of the parameters measured. Histology of banded extremities showed edema, venous and lymphatic congestion, and fibrosis compared with controls. This model of ABS in fetal lambs is simple, reproducible, and replicates all the clinical features of extremity ABS.(ABSTRACT TRUNCATED AT 250 WORDS)

First Successful Lower-Extremity Transplantation: Technique and Functional Result

Composite tissue transplantation has emerged as a viable alternative to prosthetics and complex reconstructive surgery. Thus far it is reserved for cases which cannot be effectively reconstructed and where it offers some benefits over prostheses. It has been used in the upper extremity with encouraging results and, most recently, in the face. This report outlines what is believed to be the first such use in the lower extremity. A normal lower limb in a 3-month-old ischiopagus twin who was not going to survive was transplanted to the appropriate pelvic position, revascularized, and reinnervated in an otherwise healthy sister. The limb survived and, because of the immune compatibility, did not require immune suppressive therapy. The return of muscle function in the transplanted limb is encouraging. The transplanted limb appears to be fully sensate. In addition to reinnervation, the limb is now spontaneously under the cortical control of the recipient.

Invasion and MMP expression profile in desmoid tumours

Desmoid tumours are locally invasive soft tissue tumours in which β-catenin mediated TCF-dependent transcription is activated. The role of soluble factors secreted by the myofibroblastic desmoid tumour, which could stimulate tumour invasiveness, was investigated. Using collagen gel invasion assays, the presence of factors stimulating invasion in desmoid conditioned media (CM) could be established. Since matrix metalloproteinases (MMPs) have been implicated in the process of tumoral invasion, the expression levels of the MMP family members were evaluated. Quantitative reverse transcription–PCR was used to determine the expression levels of MMP1, MMP2, MMP3, MMP7, MMP11, MMP12, MMP13, MMP14 and the inhibitors TIMP1, TIMP2 and TIMP3. Besides overexpression of MMP7, a known TCF-dependent target gene, a striking upregulation of the expression levels of MMP1, MMP3, MMP11, MMP12 and MMP13 in desmoid tumours, compared to unaffected fibroblasts from the same patients, was found. Treating the CM of desmoids with a synthetic and a physiologic MMP inhibitor reduced the invasion-stimulating capacity of the desmoid CM by approximately 50%. These results suggest the involvement of soluble factors, released by the desmoid cells, in stimulating invasion and implicate the MMPs as facilitators of invasion.

Orthopedic and Surgical Management of the Patient With Duchenne Muscular Dystrophy

Orthopedic care is an important aspect of the overall management of patients with Duchenne muscular dystrophy (DMD). In addition to progressive muscle weakness and loss of function, patients may develop joint contractures, scoliosis, and osteoporosis, causing fractures; all of these necessitate intervention by a multidisciplinary team including an orthopedic surgeon as well as rehabilitation specialists such as physio- and occupational therapists. The causes of these musculoskeletal complications are multifactorial and are related to primary effects on the muscles from the disease itself, secondary effects from weak muscles, and the related side effects of treatments, such as glucocorticoid use that affect bone strength. The musculoskeletal manifestations of DMD change over time as the disease progresses, and therefore, musculoskeletal management needs change throughout the life span of an individual with DMD. In this review, we target pediatricians, neurologists, orthopedic surgeons, rehabilitation physicians, anesthesiologists, and other individuals involved in the management of patients with DMD by providing specific recommendations to guide clinical practice related to orthopedic issues and surgical management in this setting.

Short stature as a screening test for endocrinopathy in slipped capital femoral epiphysis

Slipped capital femoral epiphysis may be associated with hypothyroidism and other endocrinopathies. Routine screening for such abnormalities is unlikely to be cost-effective since the overall incidence of these disorders, in association with slipped capital femoral epiphysis, is low. The identification of a presenting characteristic which would predict the chance of an associated endocrinopathy would allow only selected children to be screened. Our aim was to determine if certain characteristics were useful as a screen for patients with an underlying endocrinopathy who presented with slipped capital femoral epiphysis. Between January 1988 and December 1996 we recorded gender, age, height, unilateral or bilateral involvement and an associated diagnosis of endocrinopathy for all patients who were treated for slipped capital femoral epiphysis. Of 166 such patients 13 (7.8%) had an endocrinopathy. Height was the only useful screening characteristic, although bilateral involvement was more likely in those with an endocrinopathy. Most (90.9%) of this latter group were below the tenth percentile for height compared with only 5.4% in those who did not have an endocrinopathy (p < 0.005). The sensitivity and negative predictive value of detecting an underlying endocrinopathy in a patient presenting with a slipped capital femoral epiphysis and short stature (tenth percentile or less) were 90.2% and 98.6%, respectively. Patients who are on or below the tenth percentile for height at the time of presentation should be screened for a possible endocrine abnormality using measurement of thyroid-stimulating hormone and free thyroxine as a preliminary screening test. These hormones are most likely to be abnormal in the presence of endocrine dysfunction.

Reflections on current methods for evaluating skills during joint replacement surgery: a scoping review

Valid and reliable techniques for assessing performance are essential to surgical education, especially with the emergence of competency-based frameworks. Despite this, there is a paucity of adequate tools for the evaluation of skills required during joint replacement surgery. In this scoping review, we examine current methods for assessing surgeons' competency in joint replacement procedures in both simulated and clinical environments. The ability of many of the tools currently in use to make valid, reliable and comprehensive assessments of performance is unclear. Furthermore, many simulation-based assessments have been criticised for a lack of transferability to the clinical setting. It is imperative that more effective methods of assessment are developed and implemented in order to improve our ability to evaluate the performance of skills relating to total joint replacement. This will enable educators to provide formative feedback to learners throughout the training process to ensure that they have attained core competencies upon completion of their training. This should help ensure positive patient outcomes as the surgical trainees enter independent practice.

Short stature as a screening test for endocrinopathy in slipped capital femoral epiphysis

Slipped capital femoral epiphysis may be associated with hypothyroidism and other endocrinopathies. Routine screening for such abnormalities is unlikely to be cost-effective since the overall incidence of these disorders, in association with slipped capital femoral epiphysis, is low. The identification of a presenting characteristic which would predict the chance of an associated endocrinopathy would allow only selected children to be screened.

Our aim was to determine if certain characteristics were useful as a screen for patients with an underlying endocrinopathy who presented with slipped capital femoral epiphysis. Between January 1988 and December 1996 we recorded gender, age, height, unilateral or bilateral involvement and an associated diagnosis of endocrinopathy for all patients who were treated for slipped capital femoral epiphysis. Of 166 such patients 13 (7.8%) had an endocrinopathy. Height was the only useful screening characteristic, although bilateral involvement was more likely in those with an endocrinopathy. Most (90.9%) of this latter group were below the tenth percentile for height compared with only 5.4% in those who did not have an endocrinopathy (p < 0.005). The sensitivity and negative predictive value of detecting an underlying endocrinopathy in a patient presenting with a slipped capital femoral epiphysis and short stature (tenth percentile or less) were 90.2% and 98.6%, respectively.

Patients who are on or below the tenth percentile for height at the time of presentation should be screened for a possible endocrine abnormality using measurement of thyroid-stimulating hormone and free thyroxine as a preliminary screening test. These hormones are most likely to be abnormal in the presence of endocrine dysfunction.

Diagnosis of limb-girdle muscular dystrophy 2A by immunohistochemical techniques

The Western blot technique is currently the standard detection method for suspected limb girdle muscular dystrophy (LGMD) 2A (calpainopathy). This is the first report in the English literature of the successful application of immunohistochemical techniques to support a diagnosis of LGMD 2A. This approach is straightforward and appears to be reasonably specific. We propose that immunohistochemical methods should be re-evaluated for the screening of undiagnosed patients with suspected LGMD 2A.

Fracture failure mechanisms in patients with osteogenesis imperfecta

This investigation examines the failure mechanism of bone from patients with osteogenesis imperfecta (OI). Mechanical testing and ultrastructural analysis of surgically obtained bone specimens, from patients with OI and from approximately age matched normal controls, were performed. Small rectangular bone samples (1.0 mm X 1.2 mm X 15 mm) with a prismatic cross section were put under three-point bending to determine the work to fracture. Furthermore, the fracture surface was observed with scanning electron microscopy (SEM). The SEM observation of partially dissected lamellae was also performed to determine the collagen organization of the bone. The OI bone has a consistently lower work to fracture and reduced collagen organization than the normal controls. The fracture surface of the OI bone is rough and exhibits a "pull-out" type of morphology, as opposed to the smoother fracture surface of the controls. This study shows that a relatively simple mechanical test utilizing a small amount of bone can differentiate between a diseased state (OI) and a normal state of bone.

Loss of ATRX promotes aggressive features of osteosarcoma with increased NF-κB signaling and integrin binding

Osteosarcoma (OS) is a lethal disease with few known targeted therapies. Here, we show that decreased ATRX expression is associated with more aggressive tumor cell phenotypes, including increased growth, migration, invasion, and metastasis. These phenotypic changes correspond with activation of NF-κB signaling, extracellular matrix remodeling, increased integrin αvβ3 expression, and ETS family transcription factor binding. Here, we characterize these changes in vitro, in vivo, and in a data set of human OS patients. This increased aggression substantially sensitizes ATRX-deficient OS cells to integrin signaling inhibition. Thus, ATRX plays an important tumor-suppression role in OS, and loss of function of this gene may underlie new therapeutic vulnerabilities. The relationship between ATRX expression and integrin binding, NF-κB activation, and ETS family transcription factor binding has not been described in previous studies and may impact the pathophysiology of other diseases with ATRX loss, including other cancers and the ATR-X α thalassemia intellectual disability syndrome.

A shortened course of parenteral antibiotic therapy in the management of acute septic arthritis of the hip

We reviewed 20 consecutive patients with a culture-proven acute septic arthritis of the hip who were treated with a shortened course of parenteral antibiotic therapy after a surgical drainage. Patients were switched over to an oral antibiotic when they showed clinical improvement. Sixteen of the 20 patients had parenteral antibiotic therapy of <10 days, whereas nine of these patients received <7 days of parenteral therapy (mean, 8.2 days). No recurrence of infection, readmission, or osteomyelitis was observed after the discharge. At the follow-up interview (mean, 32 months), 18 patients were completely asymptomatic, and two patients had occasional hip pain with activity but no physical limitations. All 20 patients had normal hip range of motion and gait. Their latest radiographs (mean, 26 months) revealed 11 patients with normal findings, six patients with mild coxa magna, and three patients with a smaller ossific nucleus compared with the unaffected side. We conclude that a community-acquired, acute gram-positive septic arthritis of the hip can be managed safely with a surgical drainage and a shortened course of parenteral antibiotic therapy, which can be switched over to an oral therapy based on the patient's response to the therapy.