Exact solutions for transient spherical radiation.

Closed-form, analytic solutions are derived for exterior wave fields generated by the transient, axisymmetric motion of a spherical boundary. These are intended for use as benchmark problems for assessing the accuracy and correctness of transient numerical schemes. Classical Laplace transform methods are used. The derivation of these solutions is presented in sufficient detail to permit their reconstruction by the reader for multipoles of order n where 0 < or = n < or = 25. Composite solutions can also be obtained by superposition. A novel solution of this type is presented for the wave field generated by the transient motion of a spherical piston in a spherical baffle. The transient wave fields obtained in this way are shown to be consistent with steady time-harmonic solutions for large times, and with high-resolution transient numerical solutions at finite times.

Adenovirus keratitis: a role for interleukin-8.

PURPOSE: Adenovirus type 19 (Ad19) infection of the human cornea results in a chronic, multifocal, subepithelial keratitis. Existing evidence suggests that early subepithelial corneal infiltrates are composed of polymorphonuclear neutrophils. In this study, the capacity of Ad19-infected human corneal stromal fibroblasts (HCFs) to produce neutrophil chemotactants (chemokines) was tested. METHODS: HCFs grown from human donor corneas and passaged thrice were infected with a corneal isolate of Ad19 or mock-infected with virus-free media. Bioactivity of the cell supernatants was tested by a neutrophil chemotaxis assay. Supernatants were assayed by enzyme-linked immunosorbent assay for the neutrophil chemotactants interleukin-8 (IL-8) and GRO-alpha. Corneal facsimiles were generated with HCFs and collagen type I, infected with Ad19, and assayed by immunohistochemistry. RESULTS: Ad19 infection of HCFs increased neutrophil chemotaxis from a baseline of 0.4+/-0.7 cells/high-powered field (hpf; mock-infected) to 21.8+/-2.3 cells/hpf (Ad19-infected). Chemotaxis was reduced by the addition of neutralizing antibodies against IL-8 and GRO-alpha. Infection of HCFs induced quantities of IL-8 protein 300- and 1000-fold over mock-infected controls at 4 and 24 hours, respectively (33 versus 11,813 pg/mL at 4 hours, and 57 versus 76,376 pg/mL at 24 hours, P< or = 0.001 for both). In contrast, GRO-alpha protein levels were only sevenfold higher at 24 hours postinfection (118 pg/mL in mock-infected controls versus 880 pg/mL in Ad19-infected cell supernatants). Neither chemokine was induced by infection of an immortalized human corneal epithelial cell line. Immunohistochemistry of infected corneal facsimiles demonstrated IL-8 in the extracellular matrix within 3 days after infection. CONCLUSIONS: Production of chemokines in infected tissues facilitates an early innate immune response to infection, and in the infected corneal stroma represents an elementary defense mechanism. Interleukin-8 may play a role in the development of subepithelial infiltrates in adenovirus keratitis.

Metaphyseal fractures in osteogenesis imperfecta.

Forty-one children with osteogenesis imperfecta have been reviewed. A minority (7/41) showed small metaphyseal fractures, resembling those seen in non-accidental injury, but in all of these there was obvious generalized bone disease so that confusion with non-accidental injury did not occur.

Demonstration of pulmonary arteries by contrast injection into pulmonary vein.

Pulmonary venous injection of contrast medium in the near-wedge position produced a flow into the pulmonary arterial tree in 15 out of 21 children with cyanotic congenital heart disease. In 5 there was good opacification of both sides from a single injection. The technique provides an additional method of demonstrating the anatomy of the pulmonary arteries where surgical treatment is contemplated.

A 20-year prospective follow-up of childhood hiatal hernia.

A long-term prospective follow-up of 113 children with vomiting due to a small hiatal hernia is described. When reviewed by the same clinical and radiological observers 20 or more years later, over 90% of unoperated non-stricture patients were asymptomatic whereas only 44% of the stricture and/or surgically treated group were without symptoms. Half or possibly more of the asymptomatic patients still had a hernia and it is possible that these may suffer a recurrence of symptoms later in adult life. The loculus of thoracic stomach tended to retain the same shape; there was a slightly better prognosis for the locular type of hernia compared with the tubular type. Complicating oesophageal strictures can decrease or disappear without surgery other than dilatation; the results of treatment by radical surgery were disappointing. There is need for an even more prolonged follow-up into later adult life.

Pulmonary atrsia with intact ventricular septum. Open heart surgical correction at 32 hours.

A case of pulmonary atresia with intact ventricular septum is reported in which total surgical correction was carried out successfully at 32 hours of age. Cardiac catheterisation at 17 months has revealed virtually normal haemodynamic and angiographic findings. Surgical correction of this condition in the neonatal period is discussed.

A form of metatropic dwarfism in two brothers.

Two brothers are described with identical features of short-limbed dwarfism, normal face, hands and feet, respiratory difficulties and mild scoliosis. It proved impossible to offer a definitive diagnosis, though radiological features as a whole bore similarities to those of metatropic dwarfism, with the most notable feature the narrowing of the ossified components of the vertebral bodies.