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[The hereditary form of pincer nail syndrome].

Over a period of six months a 41-year-old woman had recurrent acute paronychia of both large toes. On inspection all toes had pincer nails. She had no metabolic abnormalities and no history of trauma. Onychomykosis was excluded. Under conduction anaesthesia an Emmert plasty (Haneke's modification) was performed: it revealed osteocartilaginous exostoses in the area of nail gryposis. Subsequent radiological examination showed distally directed exostoses on the tibial side of all toe phalanges, which is an obligatory criterion for the hereditary form of the pincer nail syndrome.

Acute Disease↗

The tumor suppressor EXT-like gene EXTL2 encodes an alpha1, 4-N-acetylhexosaminyltransferase that transfers N-acetylgalactosamine and N-acetylglucosamine to the common glycosaminoglycan-protein linkage region. The key enzyme for the chain initiation of heparan sulfate.

We previously demonstrated a unique alpha-N-acetylgalactosaminyltransferase that transferred N-acetylgalactosamine (GalNAc) to the tetrasaccharide-serine, GlcAbeta1-3Galbeta1-3Galbeta1-4Xylbeta1-O-Ser (GlcA represents glucuronic acid), derived from the common glycosaminoglycan-protein linkage region, through an alpha1,4-linkage. In this study, we purified the enzyme from the serum-free culture medium of a human sarcoma cell line. Peptide sequence analysis of the purified enzyme revealed 100% identity to the multiple exostoses-like gene EXTL2/EXTR2, a member of the hereditary multiple exostoses (EXT) gene family of tumor suppressors. The expression of a soluble recombinant form of the protein produced an active enzyme, which transferred alpha-GalNAc from UDP-[3H]GalNAc to various acceptor substrates including GlcAbeta1-3Galbeta1-3Galbeta1-4Xylbeta1-O-Ser. Interestingly, the enzyme also catalyzed the transfer of N-acetylglucosamine (GlcNAc) from UDP-[3H]GlcNAc to GlcAbeta1-3Galbeta1-O-naphthalenemethanol, which was the acceptor substrate for the previously described GlcNAc transferase I involved in the biosynthetic initiation of heparan sulfate. The GlcNAc transferase reaction product was sensitive to the action of heparitinase I, establishing the identity of the enzyme to be alpha1, 4-GlcNAc transferase. These results altogether indicate that EXTL2/EXTR2 encodes the alpha1,4-N-acetylhexosaminyltransferase that transfers GalNAc/GlcNAc to the tetrasaccharide representing the common glycosaminoglycan-protein linkage region and that is most likely the critical enzyme that determines and initiates the heparin/heparan sulfate synthesis, separating it from the chondroitin sulfate/dermatan sulfate synthesis.

Acetylgalactosamine↗

Identification of a receptor for reg (regenerating gene) protein, a pancreatic beta-cell regeneration factor.

Reg (regenerating gene) was isolated as a gene specifically expressed in regenerating islets (Terazono, K., Yamamoto, H., Takasawa, S., Shiga, K., Yonemura, Y., Tochino, Y., and Okamoto, H. (1988) J. Biol. Chem. 263, 2111-2114). Rat and human Reg gene products, Reg/REG proteins, have been demonstrated to stimulate islet beta-cell growth in vitro and in vivo and to ameliorate experimental diabetes. In the present study, we isolated a cDNA for the Reg protein receptor from a rat islet cDNA library. The cDNA encoded a cell surface 919-amino acid protein, and the cells into which the cDNA had been introduced bound Reg protein with high affinity. When the cDNA was introduced into RINm5F cells, a pancreatic beta-cell line that shows Reg-dependent growth, the transformants exhibited significant increases in the incorporation of 5'-bromo-2'-deoxyuridine as well as in the cell numbers in response to Reg protein. A homology search revealed that the cDNA is a homologue to a human multiple exostoses-like gene, the function of which has hitherto been unknown. These results strongly suggest that the receptor is encoded by the exostoses-like gene and mediates a growth signal of Reg protein for beta-cell regeneration.

Amino Acid Sequence↗

Epigenetic loss of the familial tumor-suppressor gene exostosin-1 (EXT1) disrupts heparan sulfate synthesis in cancer cells.

Germline mutations in the Exostoses-1 gene (EXT1) are found in hereditary multiple exostoses syndrome, which is characterized by the formation of osteochondromas and an increased risk of chondrosarcomas and osteosarcomas. However, despite its putative tumor-suppressor function, little is known of the contribution of EXT1 to human sporadic malignancies. Here, we report that EXT1 function is abrogated in human cancer cells by transcriptional silencing associated with CpG island promoter hypermethylation. We also show that, at the biochemical and cellular levels, the epigenetic inactivation of EXT1, a glycosyltransferase, leads to the loss of heparan sulfate (HS) synthesis. Reduced HS production can be reversed by the use of a DNA demethylating agent. Furthermore, the re-introduction of EXT1 into cancer cell lines displaying methylation-dependent silencing of EXT1 induces tumor-suppressor-like features, e.g. reduced colony formation density and tumor growth in nude mouse xenograft models. Screening a large collection of human cancer cell lines (n=79) and primary tumors (n=454) from different cell types, we found that EXT1 CpG island hypermethylation was common in leukemia, especially acute promyelocytic leukemia and acute lymphoblastic leukemia, and non-melanoma skin cancer. These findings highlight the importance of EXT1 epigenetic inactivation, leading to an abrogation of HS biosynthesis, in the processes of tumor onset and progression.

Animals↗

Langer-Giedion syndrome associated with submucous cleft palate.

We report a 4-year-old girl with characteristic features of the Langer-Giedion syndrome (trichorhinophalangeal syndrome type II) who also had submucous cleft palate. When she underwent a palatoplasty, a diagnosis of Langer-Giedion syndrome was made because of the characteristic facial features, multiple exostoses, and partial deletion of the long arm of chromosome 8. This is the first case of trichorhinophalangeal syndrome associated with cleft palate. We review the clinical alterations of trichorhinophalangeal syndromes and differential diagnosis of Langer-Giedion syndrome from trichorhinophalangeal syndrome type I and hereditary multiple exostoses. We also describe the importance of trichorhinophalangeal syndrome in plastic surgery.

Cephalometry↗

Distinct chromosomal rearrangements in subungual (Dupuytren) exostosis and bizarre parosteal osteochondromatous proliferation (Nora lesion).

BACKGROUND: Proliferative lesions of the bone surface, such as subungual (Dupuytren) exostosis and bizarre parosteal osteochondromatous proliferation (BPOP, Nora lesion) are currently classified as reactive, proliferative processes that mimic primary neoplasms of bone. METHODS: Cytogenetic analysis was performed on 3 subungual exostoses of the great toe and 2 BPOP lesions of the radius and ulna. RESULTS: A balanced translocation t(X;6) was identified in all cases of subungual exostoses. The chromosomal rearrangements observed in 1 case of BPOP differed from those seen in subungual exostosis. CONCLUSIONS: The presence of chromosomal abnormalities in subungual exostosis and BPOP suggests that these lesions are neoplastic, with a different molecular pathogenesis, and that each is a distinct clinicopathologic entity.

Adolescent↗

Imaging of osteochondroma: variants and complications with radiologic-pathologic correlation.

Osteochondroma represents the most common bone tumor and is a developmental lesion rather than a true neoplasm. It constitutes 20%-50% of all benign bone tumors and 10%-15% of all bone tumors. Its radiologic features are often pathognomonic and identically reflect its pathologic appearance. Osteochondromas are composed of cortical and medullary bone with an overlying hyaline cartilage cap and must demonstrate continuity with the underlying parent bone cortex and medullary canal. Osteochondromas may be solitary or multiple, the latter being associated with the autosomal dominant syndrome, hereditary multiple exostoses (HME). Complications associated with osteochondromas are more frequent with HME and include deformity (cosmetic and osseous), fracture, vascular compromise, neurologic sequelae, overlying bursa formation, and malignant transformation. Malignant transformation is seen in 1% of solitary osteochondromas and in 3%-5% of patients with HME. Continued lesion growth and a hyaline cartilage cap greater than 1.5 cm in thickness, after skeletal maturity, suggest malignant transformation. Variants of osteochondroma include subungual exostosis, dysplasia epiphysealis hemimelica, turret and traction exostoses, bizarre parosteal osteochondromatous proliferation, and florid reactive periostitis. Recognition of the radiologic spectrum of appearances of osteochondroma and its variants usually allows prospective diagnosis and differentiation of the numerous potential complications, thus helping guide therapy and improving patient management.

Biopsy↗

Arterial compromise caused by lower limb osteochondroma.

Osteochondromas occasionally cause arterial complications, mainly concerning the distal superficial femoral and popliteal arteries. The authors present 11 patients (12 cases) with arterial disorders caused by exostoses who were hospitalized in their Vascular Clinic. All but 1 had signs or symptoms of peripheral arterial disease such as intermittent claudication or diminished peripheral pulses, and 1 also presented serious neurologic sequelae. All were examined by radiography, ankle-brachial index (ABI), computed tomography scan, color duplex scan, arteriography, and scintigraphy. The popliteal artery was the most commonly affected vessel in 7 cases. In addition to the removal of the offending osteochondroma, 7 patients underwent excision of the diseased arterial segment and replacement by a saphenous vein interposition graft. The remaining 5 cases received a vein graft patch. The authors achieved good results with no serious complications detected in the immediate postoperative period and subsequent follow up. Surgical treatment of the vascular complications caused by exostoses is mandatory. Even in the absence of vascular symptoms, such bony lesions in close proximity to a vessel should be on a close follow-up in order to prevent permanent arterial damage.

Adult↗

Osteochondromas of the distal aspect of the tibia or fibula. Natural history and treatment.

BACKGROUND: There is little information on the natural history or treatment of osteochondromas arising from the distal aspect of either the tibia or the fibula. It is believed that there is a risk of deformation of the ankle if these exostoses are left untreated or if the physis or neurovascular structures are injured during operative intervention. METHODS: We reviewed the records of twenty-three patients who had been treated for osteochondroma of the distal aspect of the tibia or fibula between 1980 and 1996. Four of the patients had hereditary multiple cartilaginous exostoses. There were seventeen male and six female patients, and the average age at the time of presentation was sixteen years (range, eight to forty-eight years). RESULTS: Preoperative radiographs showed evidence of plastic deformation of the fibula in eleven patients who had a large osteochondroma. Four patients elected not to have an operation. The tumor was excised in nineteen patients. Postoperatively, all nineteen patients had a Musculoskeletal Tumor Society score of 100 percent for function of the lower extremity with pain-free symmetrical and unrestricted motion of the ankle at the latest follow-up examination. Partial remodeling of the tibia and fibula gradually diminished the asymmetry of the ankles in all nineteen operatively managed patients; however, the remodeling was most complete in the younger patients. Pronation deformities of the ankle did not change after excision of the tumor. Complications of operative treatment included four recurrences (only three of which were symptomatic), one sural neuroma, one superficial wound infection, and one instance of growth arrest of the distal aspects of the tibia and fibula. CONCLUSIONS: Osteochondromas of the distal and lateral aspects of the tibia were more often symptomatic than those of the distal aspect of the fibula; they most commonly occurred in the second decade of life with ankle pain, a palpable mass, and unrestricted ankle motion. Untreated or partially excised lesions in skeletally immature patients may become larger and cause plastic deformation of the tibia and fibula and a pronation deformity of the ankle. Ideally, operative intervention should be delayed until skeletal maturity, but, in symptomatic patients, partial excision preserving the physis may be necessary for the relief of symptoms and the prevention of progressive ankle deformity. However, partial excision is associated with a high rate of recurrence, so a close follow-up is required. Skeletally mature patients who are symptomatic may require excision of the tumor.

Adolescent↗

Popliteal pseudoaneurysm caused by an adjacent osteochondroma: a case report and review of the literature.

A male 17-year-old with multiple hereditary exostoses presented with a mass in the distal left thigh several days after lifting weights. An arteriogram showed a popliteal artery pseudoaneurysm adjacent to a femoral osteochondroma. The osteochondroma was excised and the artery was repaired with a saphenous vein interposition graft. A review of the literature identified 23 similar reports. The average age of the patients was 21.3 years. Seventy-eight percent were men and half of the patients had multiple hereditary exostoses. Ten patients were initially misdiagnosed. The clinician should consider the diagnosis of pseudoaneurysm in a young patient with an osteochondroma and a mass about the knee.

Adolescent↗

[Factors influencing morphology and function of the pharynx and pharyngoesophageal sphincter after total laryngectomy. Part II. The impact of degenerative changes in the neck segment of the vertebral column on the rest pressure within pharyngoesophageal sphincter after laryngectomy].

Radiological examinations of the vertebral column neck segment were done in 41 patients after total laryngectomy (n = 29) and laryngopharyngectomy (n = 12). Degeneration changes of different degree (from I degree to IV degree) were stated in 37 cases. Criteria of assessment were as follows: a) the width of the intervertebral space b) appearance and degree of the exostoses c) the length of the degenerative process in vertebral segment of the neck. The advanced degenerative changes in the vertebral column (IV degree) included all neck segment and were characterized by significant narrowing of the intervertebral spaces and exostoses longer than 0.5 cm. These changes were seen statistically more often in the patients after 50. The pharyngoesophageal sphincter's (p.e.s.) rest pressure was statistically rising significantly with the degree of the degeneration changes in the vertebral column. The high pressure in p.e.s. (5.7 + 2.85 kPa--43 + 21 mm Hg) was seen only in the cases of the IV degree degree. In the patients with the IV degree degree of degenerative changes in 67% retention of saliva in the hypopharynx was seen. Probably it was due to irritation of the sympathetic part of the autonomic system. The statistically significant correlation between the degree of the degenerative changes and the complains like pain during the head movement and limitation of the neck motion was also observed. In IV degree degree these complains were noted in 57% cases. The results of the investigations prove the hypothesis of influence of the sympathetic part of the autonomic system on the pharyngoesopghageal sphincter rest pressure.

Adult↗

Metachondromatosis: a report of two cases in a family.

We have described a 10-year-old Japanese boy and his father with metachondromatosis characterized by multiple exostoses, enchondromas, and periarticular calcification or ossification and reviewed the literature on this condition. The boy developed bilateral epiphyseal changes in the hips mimicking Perthes' disease. These cases are the first Japanese individuals with this disorder. The natural history and the associated disorders of metachondromatosis are also discussed in this paper. Metachondromatosis is an inherited skeletal dysplasia characterized by multiple cartilaginous exostoses, multiple enchondromas, and periarticular calcification or ossification. The mode of inheritance of the disease is autosomal dominant. In 1971, Maroteaux first described the disorder in 6 patients of 2 kindreds. Since then, 22 cases have been reported. However, no Japanese patient with this disorder has been described to date. We herein report a Japanese boy and his father with this rare bone dysplasia. The boy developed bilateral epiphyseal lesions in the femoral heads mimicking Perthes' disease.

Adult↗

[Forensic significance of anomalies in skull development].

INTRODUCTION: In the course of bone tissue development some genetic disorders such as exostoses and enostoses, may occur. Exostoses and enostoses represent bone tissue hyperplasia that can develop at any part of skeleton. Neurotrauma can cause fatal biological consequences, which is directly associated with skill development abnormalities. CASE REPORT: This is a case report of a male cadaver 36 years of age. The autopsy revealed massive hemorrhage on the left side of the neck and the right side of the lower jaw. A major fissure of the arterial wall was found on the basilar artery. A bony, wart-like excrescence was found on the clivus of the occipital bone. DISCUSSION: Coinciding ruptures and consequential bleeding from basilar artery with presence of development abnormalities in the clivus region, suggest that one has to clearly distinguish the result of the injury from anomalies already existing in the skull. The position of the attacker can be determined by concise and objective investigation. CONCLUSION: This is a case report of an anomaly in bone development: a bony, wart-like excrescence on the right side of the clivus. Due to neurotrauma and consequential sliding of brain structures, the damage of basilar artery and of the bony excrescence occurred, which led to bleeding and fatal outcome.

Adult↗

[Otosurgery in the professional rehabilitation of divers].

Factors responsible for barotraumas of the middle and internal ear of divers are discussed. A rapid, uncontrollable change in the intratympanic pressure upon diving may cause tympanum perforation, injury and displacement of auditory ossicles which, in turn, may lead to excitation of vestibular receptors. Barotraumas of the middle ear may also be produced by exostoses of the auditory meatus. The present work describes follow-up data of two divers who were grounded due to external and middle ear problems. One of them was operated on to remove bone exostoses that obturated the auditory meatus. The other diver underwent surgery to close the tympanic "barometric" perforation. After reconstructive surgery both divers resumed their professional activities. Both cases were followed-up for over three years.

Adult↗

Lack of effect of fluoride on reproductive performance and development in Shetland sheepdogs.

A 10-y history of high rates of perinatal deaths and congenital anomalies in dogs in a Shetland Sheepdog kennel prompted investigations into the cause(s). Skeletal fluorosis (mottled teeth in pups, bony exostoses in adults) followed use of a commercial dog food later found to contain 460 ppm fluoride (F) from rock phosphate added as a mineral source. The effects of the water source and fluoride in dog food on female reproduction and teratogenicity were investigated in a 2-y, 2-way factorial study in the kennel. Twenty adult shelties of proven fertility were brought into the kennel and randomized into 4 treatment groups, each consisting of 4 females and 1 male. Treatments were: Group A, high F (460 ppm) dog food, well water; Group B, high F dog food, distilled water; Group C, low F (55ppm) dog food, well water; Group D, low F dog food, distilled water. Only Group C produced as many pups as expected. Overall the missed pregnancy rate (44%) in study bitches and perinatal death rate (50%) in 48 study pups paralleled the problems in shelties resident in the kennel. Higher rates for both variables in the high F and the distilled water groups seemed likely due to chance. The only major anomaly was in Group D; minor anomalies appeared in all groups. Although 460 ppm F in dog food did produce bony exostoses, we did not find convincing evidence that it adversely affected reproduction in shelties. The cause of the reproductive problems was apparently not the dog food, water, foliage, genetic factors, or infectious disease and currently remains undetermined.

Abnormalities, Drug-Induced↗

[Valgus deformities of the ankle in children].

In children valgus deformities of the ankle joint are usually due to neurological conditions (spina bifida, poliomyelitis, spasticity). The deformity is characterized by a shortened fibula, wedging of distal tibial epiphysis and valgus tilt of the talus. Other conditions producing similar deformity include congenital and acquired fibular pseudarthroses, multiple exostoses and some cases of tarsal synostosis. Early treatment of a progressive valgus in multiple exostoses is mandatory. The author describes a case of ankle valgus following an undiagnosed traumatic section of tibialis posterior tendon. After predictable failure of a Grice procedure, a persisting good correction was obtained by fibula lengthening combined with talus reposition and fixation on os calcis.

Ankle Joint↗

[Trichorhinophalangeal syndrome. Apropos of a case].

The trichorhinopharyngeal (TRP) syndrome type I (Giedion, 1966) is characterized clinically by craniofacial dysmorphism with sparse hair, pear-shaped nose and long philtrum, and abnormalities of the extremities (disabling deformities of the hands and feet). The diagnosis is confirmed by the finding, at radiology, of cone-shaped epiphyses at the base of the middle phalanges. The discovery of patients presenting with other clinical and radiological abnormalities (growth retardation, microcephaly, mental retardation, multiple exostoses) has led to the individualization of a type II syndrome (Langer-Giedion, 1969). We report here a new case of TRP type I and review current data concerning the syndrome, notably the clinical and genetic differences between types I and II. Our case concerned a 43-year-old female patient who consulted for sparse, fine, brittle and very unaesthetic hair obliging her to wear a wig permanently. Examination disclosed other morphological abnormalities, including disabling deformities of the extremities (clinobrachydactyly of the hands and feet which had been present since the age of 6-7 years) and peculiar facial features with a globulous, pear-shaped nose and a long philtrum. She was of small size and had no mental retardation. These clinical symptoms and the finding of cone-shaped epiphyses (type 12) at the base of the middle phalanges led to affirm diagnosis of TRP type I. The case appeared to be solitary. The TRP syndrome was individualized by Giedion in 1966. It is usually detected during the later childhood. In 1969, Langer and Gorlin reported similar features in patients who, in addition, presented with multiple exostoses (hands and feet and body skeleton).(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Multiple↗

Phenytoin inhibition: failure to inhibit periosteal responses to lathyrogen.

beta-Aminopropionitrile (BAPN) administered to rats has caused exostosis formation at sites of muscle attachment and also caused delay in the healing of soft tissue wounds and of bone fractures. Since phenytoin sodium has an opposite effect on wound healing, bone fractures, and the tensile strength of connective tissues, an experiment was performed to determine whether or not BAPN could produce periosteal exostoses in the presence of phenytoin. Rats that were given both BAPN and phenytoin produced similar exostoses as rats that were given BAPN alone. This indicates that phenytoin does not prevent inhibition of lysyl oxidase by BAPN, does not promote increased tensile strength of connective tissues in the presence of BAPN, and does not facilitate the detoxification of BAPN. Further, no evidence for an increased cellular response with phenytoin was observed. The mechanism by which phenytoin promotes wound healing is still unknown.

Aminopropionitrile↗