Review article: the therapeutic potential of 5-HT3 receptor antagonists in the treatment of irritable bowel syndrome

There is evidence from studies, in both animals and humans, that 5-HT3 receptor blockade has potential value in the treatment of irritable bowel syndrome, particularly in those patients with diarrhoea-predominant bowel habits. New findings suggest that 5-HT3 receptors exist on gut afferent neurones and that their activation by locally released 5-HT leads to visceral nociceptive stimulation, in addition to increased neuronally-mediated motor and secretory activity. If this concept is validated, it will provide a rationale for the use of 5-HT3 receptor antagonists in patients with increased gut motility, reduced fluid absorption and low nociceptive thresholds leading to abdominal pain. Alosetron is a highly selective, potent 5-HT3 receptor antagonist which is well absorbed with a long pharmacodynamic half-life. Its ability to provide long-lasting blockade of 5-HT3 receptors throughout the body make it an ideal candidate within its class to evaluate the clinical hypothesis that sustained and ubiquitous 5-HT3 receptor blockade is of value in the treatment of IBS.

Mesomelic dysplasia with periosteal thickening, radio-humeral dislocation, osteoporosis and multiple fractures

We report a boy with a new form of mesomelic dysplasia characterised by short stature, multifocal periosteal thickening, radio-humeral dislocation, osteoporosis and multiple fractures with minimal trauma. Electrophoresis of fibroblast collagens detected defects in type III and type V collagen.

CONCLUSION

Bone dysplasias presenting with osteopenia, abnormal trabecular pattern, bone fragility, and periosteal thickening suggest a collagenopathy. A possible collagen defect requires biochemical investigations.

Bone dysplasias in orthopedic practice

The paper presents a review of rare but important orthopedic diseases--osteochondrodysplasias. The authors stress both the clinical and radiological variety of these deformations. Some kinds of osteochondrodysplasia are clearly defined clinical entities, while in other cases the clinical presentation is so variable that it is very difficult to make a diagnosis. Accurate diagnosis is very important in order to assess the inheritance pattern, clinical course and possible complications. Clinical and radiological examination are the cornerstones in making a diagnosis. The paper contains a list of radiograms necessary for a correct diagnosis. In many cases the diagnostic process must include highly specific biochemical and genetic tests.

Osteochondrodystrophies with marked platyspondyly and distinctive peripheral anomalies

Two patients with a unique generalised bone dysplasia demonstrating severe distinctive platyspondyly are reported. This group of crippling disorders defies metabolic and histological classification. The radiographic examination is, at present, the only practical method of documentation of these rare disorders.

Dominantly inherited isolated hyperparathyroidism: a syndromic association?

Dominantly inherited isolated hyperparathyroidism (DIIH) is rare in childhood. It may be the first biochemical abnormality in the multiple endocrine neoplasia type I (MEN I) and type II (MEN II) syndromes. Its clinical course is usually asymptomatic or of low morbidity. Radiographic examination is most often normal. We describe six members of a family with distinctive phenotype and DIIH. Limited systemic symptoms and severe radiographic osteitis fibrosa cystica were further unusual features in this family. The diagnosis of DIIH was made only after a 9-year-old girl developed hypercalcaemic crisis after a pathological femoral fracture. Distinctive phenotype, unusual clinical course and unparalleled radiographic changes suggest a not yet described syndromic association.

Burton skeletal dysplasia: the second case report

We describe a 2-year-old girl with clinical and radiological findings of Burton skeletal dysplasia. This rare disorder shows some similarities to Kniest dysplasia. Short stature, joint stiffness, microstomia, and pursed lips are characteristic clinical findings. Platyspondyly with cervical kyphosis, but no coronal clefts, and bowing of the long bones are distinctive radiographic findings.

Syndromic foramina parietalia permagna

We report on a boy with unique somatic and skeletal manifestations. The syndrome consists of branchial and auricular fistulae, abnormal face, and skeletal abnormalities including foramina parietalia permagna.

Autosomal recessive omodysplasia: report of three additional cases

Three new cases of autosomal recessive omodysplasia (ARO) are reported. One shows a new finding of craniosynostosis. One is related to a patient previously reported in 1991. Another is the first report of a patient living in Australia. The clinical and radiological findings further consolidate the condition as a distinct and readily diagnosable autosomal recessive bone dysplasia with marked limb shortening and facial abnormalities. These cases bring the total reported to 17. Names used in earlier publications include rhizomelic bone dysplasia with club-like femora, familial generalised micromelia with dislocated radius and congenital micromelic dysplasia (Borochowitz type).

Brachytelephalangic chondrodysplasia punctata

A case is reported here of a boy with brachytelephalangic chondrodysplasia punctata. This is the first case of this disorder reported in the Australian literature.

Mutation in the RIEG1 gene in patients with iridogoniodysgenesis syndrome

Axenfeld-Rieger syndrome (ARS) and iridogoniodysgenesis syndrome (IGDS) are clinically related autosomal dominant disorders which affect the anterior segment of the eye as well as non-ocular structures. ARS patients present with iris hypoplasia, a prominent Schwalbe line, adhesions between the iris stroma and the iridocorneal angle and increased intraocular pressure. IGDS is characterized by iris hypoplasia, goniodysgenesis and increased intraocular pressure. Each syndrome also presents with non-ocular features including maxillary hypoplasia, micro and anodontia, redundant periumbilical skin, hypospadius (in males), and each has been genetically linked to chromosome 4q25. RIEG1 , the gene responsible for the 4q25 ARS phenotype, recently has been cloned. RIEG1 encodes a novel member of the bicoid class of homeobox proteins known to be active as transcription factors. Mutational analysis has previously detected several mutations in this gene in ARS individuals. We have now detected a mutation in RIEG1 which segregates with the disease phenotype in a family with IGDS. This mutation is a G-->A transition altering an arginine residue to a histidine in a highly conserved location in the second helix of the homeobox of RIEG1. This mutation indicates that IGDS and ARS are allelic variants of the same disorder. This wide variability in clinical consequences of mutations at the RIEG1 4q25 locus implicates the RIEG gene broadly in ocular and craniofacial disorders.

Dysplasia epiphysealis hemimelica: clinical features and management

Dysplasia epiphysealis hemimelica is a rare developmental bone dysplasia characterized by an osteocartilaginous tumor arising from an epiphysis. We reviewed the clinical and radiographic findings, including magnetic resonance imaging (MRI), of nine new patients with dysplasia epiphysealis hemimelica. The lower limb was involved in all cases with the ankle (talus) and knee (distal femur) being the most common sites. MRI was helpful in defining the site and extent of the osteocartilaginous mass and provided detailed images of associated joint deformity. Often there was a clear plane of separation between the lesion and the normal epiphysis. All cases were observed initially and showed progressive increase in size of the lesion with skeletal growth. Surgical excision was performed in five cases and proved to be difficult. We recommend excision of symptomatic localized, juxtaarticular lesions but do not recommend excision of articular lesions. Postoperative degenerative joint changes occurred in two patients.

Brachytelephalangic chondrodysplasia punctata with distinctive phenotype and normal karyotype

We present two sibs with a distinctive phenotype and with stippled calcifications of the tarsal bones and sacro-coccygeal spine. They represent an apparently "new" form of chondrodysplasia punctata.

Generalised bone disease with abundant periosteal reaction in megakaryocytic leukaemia

We report an 18-month-old boy with trisomy 21 who presented with abundant, symmetrical periosteal hyperostosis and generalised osteolytic bone disease. Although adequate cytological and immunological studies have not been performed, the clinical course, routine blood and marrow studies allowed us to recognise megakaryoblastic leukaemia (ML) as the cause of these unique X-ray appearances.

CONCLUSION

We present a unique case of generalised bone disease in an infant with trisomy 21. The appearances--clinical course and radiographic appearances--are consistent with ML. Such severe bony changes have not yet been reported in this association. This observation widens the spectrum of ML.

Severe limb abnormalities: Nievergelt or new syndrome?

Since the characteristic mesomelic limb abnormalities of the autosomal-dominant Nievergelt syndrome (NS) may be casually nonspecific, we are unsure whether our patient with these abnormalities but also with severe, symmetrical hand and foot anomalies has an unusual form of Nievergelt syndrome or a previously apparently undescribed syndrome. This infant's condition could represent an autosomal-dominant new mutation, or an autosomal or X-linked recessive disorder.

Atelosteogenesis syndromes: a review, with comments on their pathogenesis

The clinical, radiographic, and morphological findings in 25 cases of atelosteogenesis and boomerang dysplasia have been reviewed. The review confirms the nosologic grouping of atelosteogenesis type I with boomerang dysplasia and the clinical and radiographic overlap of features between atel- osteogenesis I and atelosteogene- sis II (synonymous with De la Chapelle dysplasia) and a group of patients with atelosteogenesis type III. A common pathogenesis is suggested for atelosteogenesis type I and boomerang dysplasia. A marked excess of male fetuses with boomerang dysplasia was observed. Atelosteogenesis type II shows distinctive chondro-osseous histopathology with a major disturbance in cartilage matrix macromolecules. An overlap of phenotypic, radiographic, morphological, and cartilage histochemical features with those observed in diastrophic dysplasia and achondrogenesis type IB suggests that atelosteogenesis type II has common pathogenetic features with disorders of sulfation of connective tissue matrix macro- molecules.

Small patella syndrome: a bone dysplasia to recognize and differentiate from the nail-patella syndrome

We report a 5-year, 9-month-old boy with bilateral patellar hypoplasia. The radiographic skeletal survey revealed absent ossification of the ischium and inferior pubic ramus on both sides, characteristic of the newly recognized benign bone dysplasia known as small patella syndrome, or ischiopatellar dysplasia. No nail change, iliac horn, elbow anomaly, or renal disease is associated with this condition.

Foramina parietalia permagna: report of nine cases in one family

Nine members of a family with foramina parietalia permagna (FPP), inherited as an autosomal dominant trait are reported. Although usually benign, FPP may be associated with other malformations.

Opsismodysplasia: a case report

A 6-month-old boy with opsismodysplasia is reported. The purpose of this paper is to draw attention to severe ureteric reflux and incidence of pseudo-obstruction, findings not previously reported in opsismodysplasia. They are most likely the result of an intrinsic neuromuscular defect which also affects the skeletal muscles. Another new feature, not reported in opsismodysplasia, was dilatation of ventricles probably secondary to brain atrophy.