Dating fractures in infants.

AIM: To document the timing of the appearance of the radiological features of fracture healing in a group of infants in which the date of injury was known and to assess the degree of interobserver agreement. MATERIALS AND METHODS: Three paediatric radiologists independently assessed 161 images of 37 long bone fractures in 31 patients aged 0-44 months. The following features were assessed: soft-tissue swelling, subperiosteal new bone formation (SPNBF), definition of fracture line, presence or absence of callus, whether callus was well or ill defined, and the presence of endosteal callus. RESULTS: Agreement between observers was only moderate for all discriminators except SPNBF. SPNBF was invariably seen after 11 days but was uncommon before this time even in the very young. In one case SPNBF was seen at 4 days. CONCLUSION: With the exception of SPNBF, the criteria relied on to date fractures are either not reproducible or are poor discriminators of fracture age.

Radiological features of Meckel's diverticulum and its complications.

Meckel's diverticulum is the most common congenital abnormality of the small bowel. The majority of patients with this anomaly will remain asymptomatic; however, several complications may occur, including obstruction, intussusception, perforation, diverticulitis, and gastrointestinal haemorrhage. These complications may produce a variety of different clinical features and radiological appearances. The purpose of this article is to review the potential imaging manifestations of Meckel's diverticulum and its complications and discuss the advantages and disadvantages of the imaging techniques available.

Cervical spine injuries to children under 11: should we use radiography more selectively in their initial assessment?

OBJECTIVES: To assess the effectiveness of cervical spine radiography in injured children under 11 years old, and suggest improvements. METHODS: Retrospective survey of radiographs and accident and emergency records for children examined during a one year period in a large teaching hospital. RESULTS: No cervical spine fractures occurred in this age group during the year. The recorded clinical findings did not always justify radiography. CONCLUSIONS: Clinical examination appears undervalued by those assessing injured children and is poorly recorded. Radiography can be used more selectively. Initial assessment using a single lateral projection can be followed in doubtful cases by cross sectional imaging.

Infection of murine keratinocytes with herpes simplex virus type 1 induces the expression of interleukin-10, but not interleukin-1 alpha or tumour necrosis factor-alpha.

Herpes simplex virus (HSV) is known to possess several mechanisms whereby it can evade the normal host immune defences. In this study the expression of the immunosuppressive cytokine, interleukin (IL)-10, was monitored following infection of a murine keratinocyte cell line (PAM-212) and compared with the expression of two proinflammatory cytokines: IL-1 alpha and tumour necrosis factor (TNF)-alpha. The PAM-212 cells were infected at a multiplicity of 0.5 with a clinical isolate of HSV type 1, and the mRNA of the three cytokines was assessed by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) over the following 24 hr. By 12 hr postinfection the amount of IL-10 mRNA had increased significantly to five-fold greater than that found in uninfected cells (P < 0.01), and this elevated level was maintained until at least 24 hr postinfection. In contrast, IL-1 alpha and TNF-alpha mRNAs were not significantly up-regulated by the HSV infection. Immunostaining with an IL-10 monoclonal antibody (mAb) revealed that cytoplasmic IL-10 protein had increased by 6-12 hr postinfection. This quantity was further increased at 24 hr postinfection, when the viral cytopathic effect was apparent. Viral replication was necessary, but not sufficient on its own, for IL-10 induction. Experiments with HSV mutants lacking functional transactivating factors suggested that the viral transactivating proteins ICP-0 and VP-16 may be necessary for HSV-induced IL-10 expression. Thus, the up-regulation in the expression of IL-10 mRNA and protein induced by HSV early in the infection of keratinocytes represents a specific response and may be part of the viral strategy to avoid local immune defence mechanisms in the skin.

Differential effect of phototherapy on the activities of human natural killer cells and cytotoxic T cells.

Exposure to ultraviolet B (UV-B) light is recognized to induce suppression of certain immune responses, particularly delayed hypersensitivity. However, its effect on cytotoxic T lymphocyte (CTL) activity, of major importance in the resistance to viruses and tumours, has not been assessed to the same extent. In this study five normal subjects, seropositive for herpes simplex virus (HSV), underwent a standard course of broadband UV-B therapy, as used in the treatment of psoriasis. They received whole-body irradiation thrice weekly for four weeks with incremental doses dependent on skin type. Blood samples were taken immediately before, at two time points during, and at the end of the therapy. An HSV-specific CTL assay was performed using autologous B cells transformed with Epstein-Barr virus as targets. No consistent modulation in CTL activity was obtained as a result of the therapy. The CTLs were separated into CD4 and CD8 subsets by positive selection and, again, no effect of irradiation on CTL activity within each of these two populations was observed. In contrast, the natural killer (NK) cell activity, assessed by the lysis of K562 cells, was significantly reduced at the first time point after the initiation of the phototherapy in all five subjects, and it continued to decline as the treatment progressed. Thus a differential effect of UV-B exposure on cytotoxic activity has been demonstrated: the HSV-specific CTL response is unchanged, while the NK response is suppressed.

Intra-abdominal fluid collections after liver transplantation.

Fluid collections are commonly seen following orthotopic liver transplantation. The majority of these collections are not infected and resolve spontaneously. However, infected collections are associated with significant morbidity and mortality and usually require drainage. Clinical signs of infection are frequently masked following transplantation due to immunosuppression. Intrahepatic collections usually represent abscesses or bilomas and invariably require intervention. Altered anatomical relationships result in signs that frequently help to differentiate these from loculated fluid within hepatic fissures. Other imaging features indicating infection include the presence of gas where none was seen previously, the development of a discrete wall and changes in the surrounding liver.

Draped aorta: CT sign of contained leak of aortic aneurysms.

PURPOSE: To evaluate the usefulness of a new computed tomographic (CT) sign of "draped aorta" in the diagnosis of a contained leak in an aortic aneurysm. MATERIALS AND METHODS: CT scans were retrospectively evaluated in 10 patients in whom an unidentifiable aortic wall and posterior aspect of the aorta that followed the vertebral contour were seen. CT findings were compared with those at surgery. RESULTS: Seven patients had a deficient aortic wall and a contained leak. Two patients had a deficient wall and a mycotic aneurysm. One patient had a false aneurysm at the aortic graft anastomosis. CONCLUSION: On CT images, draping of the aorta if highly indicative of deficiency of the aortic wall and a contained leak.

Case report: colonic obstruction following small bowel barium study.

A case is described in which inspissated barium was retained in the colon for 16 months before causing large bowel obstruction. To our knowledge this is the first case described in which the time interval between barium ingestion and the onset of symptoms was more than a few weeks. Scybalum formation is due to resorption of water from the barium sulphate, which although less common with modern preparations, still appears to be possible in certain high-risk patients. Prolonged retention of barium should be avoided by increased awareness of the problem, encouraging patients to eat and drink normally after the examination, encouraging mobility and administration of lactulose in high risk patients.